Generation of two iPSC lines (MHHi001-A-12 and MHHi001-A-13) carrying biallelic truncating mutations at the 3'-end of SRCAP using CRISPR/Cas9

Non-Floating Harbour Syndrome (FLHS) neurodevelopmental disorder (NDD) is a recently described disorder caused by mutations in certain regions of the SRCAP gene. We generated two iPSC lines that contain truncating mutation on both alleles at the 3'-end of SRCAP using CRISPR/Cas9 technology. Both cell lines are pluripotent, differentiate into the 3 germ layers and contain no genomic aberrations or off-target modifications. The cell lines form part of a human disease model to investigate the effects of truncating mutations in different regions of SRCAP.

Sulindac sulfide as a non-immune suppressive γ-secretase modulator to target triple-negative breast cancer

Introduction

Triple-negative breast cancer (TNBC) comprises a heterogeneous group of clinically aggressive tumors with high risk of recurrence and metastasis. Current pharmacological treatment options remain largely limited to chemotherapy. Despite promising results, the efficacy of immunotherapy and chemo-immunotherapy in TNBC remains limited. There is strong evidence supporting the involvement of Notch signaling in TNBC progression. Expression of Notch1 and its ligand Jagged1 correlate with poor prognosis. Notch inhibitors, including g-secretase inhibitors (GSIs), are quite effective in preclinical models of TNBC. However, the success of GSIs in clinical trials has been limited by their intestinal toxicity and potential for adverse immunological effects, since Notch plays key roles in T-cell activation, including CD8 T-cells in tumors. Our overarching goal is to replace GSIs with agents that lack their systemic toxicity and ideally, do not affect tumor immunity. We identified sulindac sulfide (SS), the active metabolite of FDA-approved NSAID sulindac, as a potential candidate to replace GSIs.

Methods

We investigated the pharmacological and immunotherapeutic properties of SS in TNBC models in vitro, ex-vivo and in vivo.

Results

We confirmed that SS, a known γ-secretase modulator (GSM), inhibits Notch1 cleavage in TNBC cells. SS significantly inhibited mammosphere growth in all human and murine TNBC models tested. In a transplantable mouse TNBC tumor model (C0321), SS had remarkable single-agent anti-tumor activity and eliminated Notch1 protein expression in tumors. Importantly, SS did not inhibit Notch cleavage in T- cells, and the anti-tumor effects of SS were significantly enhanced when combined with a-PD1 immunotherapy in our TNBC organoids and in vivo.

Discussion

Our data support further investigation of SS for the treatment of TNBC, in conjunction with chemo- or -chemo-immunotherapy. Repurposing an FDA-approved, safe agent for the treatment of TNBC may be a cost-effective, rapidly deployable therapeutic option for a patient population in need of more effective therapies.

The effect of smoking on union rates following corrective osteotomies around the knee: A systematic review and meta-analysis

BACKGROUND

Distal femur osteotomies (DFO) and high tibial osteotomies (HTO), are well-established treatment options for joint preservation in active patients with uni-compartmental osteoarthritis. Optimal outcomes are contingent on adequate preoperative evaluation of patient-specific factors. This systematic review and meta-analysis aims to explore the difference in union rates between smokers and non-smokers following corrective osteotomies around the knee.

METHODS

A systematic search of the MEDLINE and EMBASE databases was performed in accordance with the PRISMA guidelines to identify studies reporting smoking status in adults who developed delayed and/or non-union following HTO or DFO. Studies were pooled using a random effect model [Review Manager (RevMan) software, V.5.4] and heterogeneity was estimated using I2.

RESULTS

Data for meta-analysis was available for 1,406 osteotomies from 10 studies, performed in patients with mean age ranging from 38-54 years, and 65% were male. The union rate among non-smokers was 97.3% (1100/1131) compared with 89.5% (246/275) among smokers; OR 4.59 [95% CI 1.99 to 10.62], p-value < 0.001. Subgroup analysis revealed that the risk of non-union in smokers after opening wedge osteotomy was almost double (OR 4.8) that of closing wedge osteotomies (OR 2.9).

CONCLUSION

Smoking increases the risk of non-union during elective knee osteotomy surgery. Our findings also suggest that smokers have a better chance of achieving union with closing wedge osteotomy compared to open wedge osteotomy.

The Efficacy of CB-103, a First-in-Class Transcriptional Notch Inhibitor, in Preclinical Models of Breast Cancer

BACKGROUND

The efficacy of CB-103 was evaluated in preclinical models of both ER+ and TNBC. Furthermore, the therapeutic efficacy of combining CB-103 with fulvestrant in ER+ BC and paclitaxel in TNBC was determined.

METHODS

CB-103 was screened in combination with a panel of anti-neoplastic drugs. We evaluated the anti-tumor activity of CB-103 with fulvestrant in ESR1-mutant (Y537S), endocrine-resistant BC xenografts. In the same model, we examined anti-CSC activity in mammosphere formation assays for CB-103 alone or in combination with fulvestrant or palbociclib. We also evaluated the effect of CB-103 plus paclitaxel on primary tumors and CSC in a GSI-resistant TNBC model HCC1187. Comparisons between groups were performed with a two-sided unpaired Students' t-test. A one-way or two-way ANOVA followed by Tukey's post-analysis was performed to analyze the in vivo efficacy study results.

THE RESULTS

CB-103 showed synergism with fulvestrant in ER+ cells and paclitaxel in TNBC cells. CB-103 combined with fulvestrant or paclitaxel potently inhibited mammosphere formation in both models. Combination of CB-103 and fulvestrant significantly reduced tumor volume in an ESR1-mutant, the endocrine-resistant BC model. In a GSI-resistant TNBC model, CB-103 plus paclitaxel significantly delayed tumor growth compared to paclitaxel alone.

CONCLUSION

our data indicate that CB-103 is an attractive candidate for clinical investigation in endocrine-resistant, recurrent breast cancers with biomarker-confirmed Notch activity in combination with SERDs and/or CDKis and in TNBCs with biomarker-confirmed Notch activity in combination with taxane-containing chemotherapy regimens.

TB treatment using family members, treatment supporters and self-administered therapies in rural Papua New Guinea

SETTING

Papua New Guinea (PNG) has one of the world's highest TB incidence rates. It is difficult for patients to access TB care in remote provinces due to insufficient infrastructure and challenging terrain, making varied, targeted delivery models for treating TB necessary.

OBJECTIVE

To assess treatment outcomes using self-administered treatment (SAT), family-supported treatment and community-based directly observed therapy (DOT) via treatment supporter (TS) in the PNG context.

DESIGN

A retrospective, descriptive analysis of routinely collected data from 360 patients at two sites in 2019-2020. All patients were assigned a treatment model based on risk factors (adherence or default) and offered patient education and counselling (PEC), family counselling and transportation fees. End-of-treatment outcomes were assessed for each model.

RESULTS

Treatment success rates among drug-susceptible TB (DS-TB) were good overall: 91.1% for SAT, 81.4% for family-supported treatment and 77% for DOT patients. SAT was strongly associated with favourable outcomes (OR 5.7, 95% CI 1.7-19.3), as were PEC sessions (OR 4.3, 95% CI 2.5-7.2).

CONCLUSION

By considering risk factors when determining their treatment delivery model, strong outcomes were seen in all three groups. Multiple modes of treatment administration, tailored to individuals' needs and risk factors, is a feasible, effective, patient-centred care model for hard-to-reach, resource-limited settings.

H2S Prodrug, SG-1002, Protects against Myocardial Oxidative Damage and Hypertrophy In Vitro via Induction of Cystathionine β-Synthase and Antioxidant Proteins

Endogenously produced hydrogen sulfide (H₂S) is critical for cardiovascular homeostasis. Therapeutic strategies aimed at increasing H₂S levels have proven cardioprotective in models of acute myocardial infarction (MI) and heart failure (HF). The present study was undertaken to investigate the effects of a novel H₂S prodrug, SG-1002, on stress induced hypertrophic signaling in murine HL-1 cardiac muscle cells. Treatment of HL-1 cells with SG-1002 under serum starvation without or with H₂O₂ increased the levels of H₂S, H₂S producing enzyme, and cystathionine β-synthase (CBS), as well as antioxidant protein levels, such as super oxide dismutase1 (SOD1) and catalase, and additionally decreased oxidative stress. SG-1002 also decreased the expression of hypertrophic/HF protein markers such as atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), galectin-3, TIMP1, collagen type III, and TGF-β1 in stressed HL-1 cells. Treatment with SG-1002 caused a significant induction of cell viability and a marked reduction of cellular cytotoxicity in HL-1 cells under serum starvation incubated without or with H₂O₂. Experimental results of this study suggest that SG-1002 attenuates myocardial cellular oxidative damage and/or hypertrophic signaling via increasing H₂S levels or H₂S producing enzymes, CBS, and antioxidant proteins.

Procalcitonin versus C-Reactive Protein as a Biomarker for Prediction of Bacterial Infection in Children with Febrile Neutropenia in Acute Leukemia

Febrile neutropenia (FN) is a frequently occurring treatment-related complication with significant morbidity and mortality for childhood acute leukemia. Early diagnosis and assessment of severity are essential steps for early comprehensive treatment to reduce FN-related morbidity and mortality. Biomarkers like C-reactive protein (CRP) and procalcitonin (PCT) can be used to assess and predict the bacterial infection in children with febrile neutropenia. The objective of the study was to determine the role of procalcitonin and CRP as a biomarker for prediction of bacterial infection in children with FN in acute leukemia. This prospective observational study was conducted in the Department of Pediatric Hematology and Oncology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh from August 2020 to July 2021. Total 58 Children with acute leukemia aged 1 to <18 years with FN were analyzed in this study. A proper history and thorough physical examination were carried out. The blood sample was sent for biomarkers (Procalcitonin and CRP) within 24 hours of the onset of FN and other investigations, such as Complete blood count, Blood C/S, Urine R/E and C/S. Metabolic workup (SGPT, Serum Creatinine, Serum Electrolytes, Serum Ca+) was also done in every patient. Stool R/E & C/S, Chest X-ray, Wound swab for C/S were done when the patient presented with diarrhoea, cough, respiratory distress and focal sepsis respectively. In this study, the mean age of the patients was 6.62±4.07 years (1.10-16.0 years) and 34 patients (58.6%) were male. In 65.5% of patients, localizing signs of infection were not identified. Of the 58 patients, 12 patients (20.7%) showed positive blood culture and 2 patients (3.4%) showed positive urine culture. Klebsiella spp (41.0%) was the most frequent organism isolated followed by Acinetobacter (17.0%), Pseudomonas (17.0%) and E. coli (17.0%). The median PCT levels were significantly higher in patients with bacterial infection than patients without bacteremia (26.10μg/l versus 0.78μg/l, p=0.002) and PCT level >2μg/l was significantly associated with bacteremia. The median CRP levels in the bacteremia and without-bacteremia patients were 137.4mg/L and 54.17mg/L, respectively (p=0.036). In direct comparisons, PCT showed better overall performance than CRP with the AUC being 0.797 (95% CI 0.651-0.943) for PCT and 0.697 (95% CI 0.54-0.855) for CRP in predicting the bacterial infection. PCT and CRP both are useful biomarkers for the prediction of bacteremia, but PCT may be a superior early biomarker as compared to CRP to predict bacterial infection in children with febrile neutropenia in acute leukemia.

Targeting the Cbl-b-Notch1 axis as a novel immunotherapeutic strategy to boost CD8+ T-cell responses

A critical feature of cancer is the ability to induce immunosuppression and evade immune responses. Tumor-induced immunosuppression diminishes the effectiveness of endogenous immune responses and decreases the efficacy of cancer immunotherapy. In this study, we describe a new immunosuppressive pathway in which adenosine promotes Casitas B-lineage lymphoma b (Cbl-b)-mediated Notch1 degradation, causing suppression of CD8+ T-cells effector functions. Genetic knockout and pharmacological inhibition of Cbl-b prevents Notch1 degradation in response to adenosine and reactivates its signaling. Reactivation of Notch1 results in enhanced CD8+ T-cell effector functions, anti-cancer response and resistance to immunosuppression. Our work provides evidence that targeting the Cbl-b-Notch1 axis is a novel promising strategy for cancer immunotherapy.

Abstract 2525: Understanding triple-negative breast cancer immune microenvironment by disease stages, obesity, and race

Background: Triple-negative breast cancer (TNBC) is a molecularly heterogeneous group of clinically aggressive malignancies. There are well-recognized health disparities in TNBC outcomes, and the risk of TNBC is higher among African-Americans (AA). It is unclear whether immunological features of the tumor microenvironment (TME) associated with disease stage, socioeconomic factors, or comorbidities such as obesity may affect tumor immunity. The incidence of TNBC and obesity in Louisiana is among the highest in the nation, and we have documented disparities in incidence linked to race and disparities in mortality linked to social determinants of health. Recent studies described immunologic characteristics of the TNBC TME. However, the possible association of immunogenomic portraits of TNBCs with race, comorbidities or socioeconomic factors remains understudied.

Methods: We studied the expression of immunity-associated genes in clinically annotated TNBCs from Louisiana AA and European-American (EA) patients with or without obesity. Primary invasive breast cancer cases with confirmed TNBC diagnosis were identified by the Louisiana Tumor Registry (LTR). Sections of FFPE tissue containing ≥ 50% tumor were identified and processed for RNA-Sequencing [(n = 256; White women:125 (Lean: 50 and Obese:75) and Black women:131 (Lean:28 and Obese: 103)] at Translational Genomic Core, LSUHSC. Categorical outcomes were compared via Chi-squared tests, and survival was compared via log-rank tests. Spearman correlation analysis was used to determine associations between CIBERSORT cell populations and stage of disease at diagnosis.

Results: We found that race was associated with the stage of TNBC, and AA patients were more often diagnosed with a later stage of TNBC (p=0.0447). However, race was not associated with survival (p=0.4673). Obesity was not associated with stage at diagnosis (p=0.7256). Stage at diagnosis was the strongest determinant of survival (p&lt;0.0001). We utilized CIBERSORT analysis to identify and quantify immune cell populations within the TME. Later stage at diagnosis was associated with increased T follicular helper cells (p=0.0038), M1 macrophages (p= 0.0032), and activated mast cells (p=0.0487). Conversely, later stage of disease was associated with decreased resting mast cells (p=0.0004) and monocytes (p=0.0455). Immunosuppressive Treg cells were positively associated with stage at diagnosis in AA patients (p=0.0273) but not in EA patients (p=0.9141).

Conclusions: Stage at diagnosis was the strongest determinant of survival and was associated with significant differences in TME immune cell populations. Stage, race and obesity were associated with the presence of immunosuppressive Treg cells. If confirmed, these findings may help understand the variability in immunotherapy responses in TNBC.

Citation Format: Fokhrul Hossain, Denise Danos, Jovanny Zabaleta, Jiande Wu, Mary Anne Lynch, Luis Del Valle, Xiao-Cheng Wu, Augusto Ochoa, Chindo Hicks, Lucio Miele. Understanding triple-negative breast cancer immune microenvironment by disease stages, obesity, and race [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 2525.

Obesity Modulates the Gut Microbiome in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an aggressive, molecularly heterogeneous subtype of breast cancer. Obesity is associated with increased incidence and worse prognosis in TNBC through various potential mechanisms. Recent evidence suggests that the gut microbiome plays a central role in the progression of cancer, and that imbalances or dysbiosis in the population of commensal microbiota can lead to inflammation and contribute to tumor progression. Obesity is characterized by low-grade inflammation, and gut dysbiosis is associated with obesity, chronic inflammation, and failure of cancer immunotherapy. However, the debate on what constitutes a "healthy" gut microbiome is ongoing, and the connection among the gut microbiome, obesity, and TNBC has not yet been addressed. This study aims to characterize the role of obesity in modulating the gut microbiome in a syngeneic mouse model of TNBC. 16S rRNA sequencing and metagenomic analyses were performed to analyze and annotate genus and taxonomic profiles. Our results suggest that obesity decreases alpha diversity in the gut microbiome. Metagenomic analysis revealed that obesity was the only significant factor explaining the similarity of the bacterial communities according to their taxonomic profiles. In contrast to the analysis of taxonomic profiles, the analysis of variation of functional profiles suggested that obesity status, tumor presence, and the obesity-tumor interaction were significant in explaining the variation of profiles, with obesity having the strongest correlation. The presence of tumor modified the profiles to a greater extent in obese than in lean animals. Further research is warranted to understand the impact of the gut microbiome on TNBC progression and immunotherapy.

Precision Medicine and Triple-Negative Breast Cancer: Current Landscape and Future Directions

Simple Summary

The implementation of precision medicine will revolutionize cancer treatment paradigms. Notably, this goal is not far from reality: genetically similar cancers can be treated similarly. The heterogeneous nature of triple-negative breast cancer (TNBC) made it a suitable candidate to practice precision medicine. Using TNBC molecular subtyping and genomic profiling, a precision medicine-based clinical trial is ongoing. This review summarizes the current landscape and future directions of precision medicine and TNBC.

Abstract

Triple-negative breast cancer (TNBC) is an aggressive and heterogeneous subtype of breast cancer associated with a high recurrence and metastasis rate that affects African-American women disproportionately. The recent approval of targeted therapies for small subgroups of TNBC patients by the US ‘Food and Drug Administration’ is a promising development. The advancement of next-generation sequencing, particularly somatic exome panels, has raised hopes for more individualized treatment plans. However, the use of precision medicine for TNBC is a work in progress. This review will discuss the potential benefits and challenges of precision medicine for TNBC. A recent clinical trial designed to target TNBC patients based on their subtype-specific classification shows promise. Yet, tumor heterogeneity and sub-clonal evolution in primary and metastatic TNBC remain a challenge for oncologists to design adaptive precision medicine-based treatment plans.

Racial Disparities in Triple Negative Breast Cancer: A Review of the Role of Biologic and Non-biologic Factors

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that lacks expression of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER2). TNBC constitutes about 15–30 percent of all diagnosed invasive breast cancer cases in the United States. African-American (AA) women have high prevalence of TNBC with worse clinical outcomes than European-American (EA) women. The contributing factors underlying racial disparities have been divided into two major categories based on whether they are related to lifestyle (non-biologic) or unrelated to lifestyle (biologic). Our objective in the present review article was to understand the potential interactions by which these risk factors intersect to drive the initiation and development of the disparities resulting in the aggressive TNBC subtypes in AA women more likely than in EA women. To reach our goal, we conducted literature searches using MEDLINE/PubMed to identify relevant articles published from 2005 to 2019 addressing breast cancer disparities primarily among AA and EA women in the United States. We found that disparities in TNBC may be attributed to racial differences in biological factors, such as tumor heterogeneity, population genetics, somatic genomic mutations, and increased expression of genes in AA breast tumors which have direct link to breast cancer. In addition, a large number of non-biologic factors, including socioeconomic deprivation adversities associated with poverty, social stress, unsafe neighborhoods, lack of healthcare access and pattern of reproductive factors, can promote comorbid diseases such as obesity and diabetes which may adversely contribute to the aggression of TNBC biology in AA women. Further, the biological risk factors directly linked to TNBC in AA women may potentially interact with non-biologic factors to promote a higher prevalence of TNBC, more aggressive biology, and poor survival. The relative contributions of the biologic and non-biologic factors and their potential interactions is essential to our understanding of disproportionately high burden and poor survival rates of AA women with TNBC.

Abstract PO-155: Social determinants of receptor positive breast cancer patients’ survival in Louisiana

Breast carcinoma is the most commonly diagnosed cancer in Louisiana women. Four molecular subtypes of breast cancer are classified by the presence or lack of certain hormone receptors (HR), specifically estrogen and progesterone receptors, and the Human epidermal growth factor 2 (HER2) including: Luminal A (HR+/HER2-), Luminal B (HR+/HER2+), HER2-enriched (HR-/HER2+), and Triple-Negative Breast Cancer, TNBC (HR-/HER2-). Although it is now known that genetics has a role in the risk of breast cancer incidence, other factors such as age, race, and neighborhood also have an effect on prognosis and survival. Previously we have reported that in Louisiana neighborhood concentrated disadvantage index (CDI) explained the racial disparities in TNBC stage at diagnosis and survival, but not the disparities present in incidence. The purpose of this study is to assess the association of social determinants in Luminal A, Luminal B, and HER2-enriched breast cancers patients’ survival. This population-based study used 2010-2016 breast cancer data from the Louisiana Tumor Registry (LTR) and the data of the population at risk was obtained from the US Census. To assess neighborhood environment, CDI scores were calculated based on the PhenX Toolkit Protocol. We performed regression analysis of survival data based on the cox proportional hazard models using PHREG. A total of 21,005 breast cancer patient’s data were initially screened for the study with Luminal A (14,437), Luminal B (2,345), HER2-enriched (1,089) and TNBC (3134) diagnosis. Caucasian women (White) represented 68.5%, African women (Black) represented 30.42% and “other” race represented 1.09% of the breast cancer patients. Using Wald Chi-square tests, we compared stage of diagnosis (distant, regional) and CDI among Black and White patients of all three receptor positive breast cancers. For Luminal A, stage of diagnosis, [Distant: (Pr&gt;ChiSq &lt;0.0001), Hazard Ratio, HR:32.4] and Regional: (Pr&gt;ChiSq &lt;0.0001), HR:3.56], and race (Pr&gt;ChiSq &lt;0.0001, HR:1.58]) were significant, but not the CDI [(Pr&gt;ChiSq: &lt; 0.812), HR:1.0]. For Luminal B, stage of diagnosis, [Distant: (Pr&gt;ChiSq &lt;0.0001), HR:30.17] and Regional: (Pr&gt;ChiSq &lt;0.0001), HR:4.49], and race (Pr&gt;ChiSq &lt;0.0065, HR:1.62]) were significant, but not the CDI [(Pr&gt;ChiSq: &lt; 0.288), HR:0.91]. For HER2, stage of diagnosis, [Distant: (Pr&gt;ChiSq &lt;0.0001), HR:14.798] and Regional: (Pr&gt;ChiSq &lt;0.0001), HR:2.765], was significant, but race (Pr&gt;ChiSq &lt;0.254, HR:1.26]) and CDI [(Pr&gt;ChiSq: &lt; 0.75), HR:1.0] were not. We found significant racial difference in survival in Luminal A and Luminal B breast cancer subtypes but not in HER2-enriched subtype. However, we didn’t find any significant contribution of CDI in receptor positive breast cancer patient survival.

Future studies should focus on assessing the processes by which social determinants affect receptor positive breast cancer disease progression.

Citation Format: Alejandra M. Rivera-Irizarry, Denise Danos, Xinnan Wang, Qiufan Fu, Xiao-Cheng Wu, Richard Scribner, Lucio Miele, Fokhrul Hossain. Social determinants of receptor positive breast cancer patients’ survival in Louisiana [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-155.

Abstract 6691: Delivering intra-tumoral immune modulators and targeting cancer stem cells using recombinant- AAVs

Solid tumors are composed of heterogeneous cell populations that support rapid growth of cancer cells and suppress immune cell responses. Unleashing the body's own immune response to eradicate cancer cells is one of the most promising ways to treat cancer patients. However, cancer immunotherapy is not without challenges. Some of these include:

1) Phenotypic plasticity and clonal selection in a highly dynamic, heterogeneous and mutable cell population, which leads to de novo and acquired resistance;

2) Immune editing by cancer cells;

3) Expression of immune check point ligands and receptors to suppress immune response locally within the tumor microenvironment, and systemically using exosomes as immune checkpoint carriers;

4) Cross-talk between cancer stem cells and the immune microenvironment;

5) Feasibility of developing personalized treatment strategies, such as cost vs benefit of CAR-T-cell therapy and time constraint, and humanized antibody production;

6) Systemic toxicity of current immunotherapy strategies;

To address these challenges, we propose to use a recombinant adeno-associated virus (rAAV) platform to simultaneously enhance tumor immunity and target cancer stem cells by intra-tumoral administration. We express programmed cell death ligand-1 (PD-L1), and B7-H3 (CD276), in combination with a Notch1 decoy. The latter was chosen because: 1) Notch is a crucial signaling component of cancer stem cells (CSCs) maintenance and resistance and 2) Studies have shown that within the tumor, regulatory T-cells (Treg) are activated by OX40 and Notch ligand Jagged1. Blocking Notch signaling would have dual advantages: blocking Notch signaling in CSCs, and preventing activation of immunosuppressive Tregs.

Based on current clinical trials and our experimental results, we hypothesized that intra-tumoral injection of rAAV viral particles engineered to express soluble PD-1, B7-H3 and Notch1 decoys in combination with lipopolysaccharide (LPS) is a promising strategy. To test our hypothesis, we used two mouse triple negative breast (TNBC) cancer models: C0321 in the FVB background and M-Wnt in the C57/Bl6 background; both are aggressive, highly metastatic, and similar to human TNBC. Using tumor spheroids in vitro, in the presence of soluble decoys of PD-1, B7-H3 and Notch1 synergistically induced the most effective tumor cell killing, compared to single decoy application. Importantly, intra-tumoral injection of PD-1, B7-H3 and Notch1 decoys in combination with LPS induced necrosis of tumors in vivo in our preliminary findings.

Citation Format: Deniz A. Ucar, Giulia Monticone, Fokhrul Hossain, Samarpan Majumder, Dorota Wyczechowska, Matthew J. Dean, Luis Del Valle, Jovanny Zabaleta, Yong Ran, Sudarvili Shanthalingam, Abraham Bert Chabot, Bridgette M. Collins-Burow, Matthew E. Burrow, Barbara Osborne, Todd Eliot Golde, Lucio Miele. Delivering intra-tumoral immune modulators and targeting cancer stem cells using recombinant- AAVs [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 6691.

Abstract 3866: Investigating tumor infiltrating immune cells signature in obese triple negative breast cancer

Triple negative breast cancer (TNBC) is a heterogeneous group of clinically aggressive breast cancers and TNBC patients are pathologically negative for estrogen receptor (ER−), progesterone receptor (PR−), and human epidermal growth factor receptor 2 (HER2−) amplification, which impedes the use of targeted therapies used in other breast cancer subtypes. Obesity is a chronic state of inflammation and is associated with increased secretion of pro-inflammatory cytokines, increased infiltration of immune cells and the development of a microenvironment that supports tumor growth. Several epidemiological studies support the association of obesity with TNBC; however, the underlining molecular mechanisms remain unknown. We developed an immunocompetent obese FVB (female) mouse model by feeding ‘Western diet' or control diet for four months and then injecting with syngeneic C0321 (mouse TNBC) cells to investigate the immune signatures and to study the role of obesity related factors in TNBC progression. We found significant body weight increases in ‘Western diet' fed mice group as expected. The percentage of CD8+ and CD4+ T cells, and macrophages in spleen, liver and peripheral blood in obese mice did not change significantly compared to lean mice. However, the percentages of immunosuppressive Myeloid Derived Suppressor cells (MDSCs), particularly Monocytic-MDSCs were elevated in liver and visceral fat tissue in obese mice. Importantly, tumors in ‘Western Diet' fed mice achieved significantly larger volumes. We found no noticeable difference in the percentage of CD8+ and CD4+ T cells, MDSC or macrophages in the spleen of tumor bearing obese mice. Interestingly, there was a decreasing trend in tumor infiltrating CD8+ and CD4+ T cells in tumor bearing obese mice. Further, tumor infiltrating myeloid cells, MDSCs and macrophages were significantly increased in obese mice, suggesting the formation of an immunosuppressive environment. More importantly, tumor infiltrating MDSCs from obese mice were more immunosuppressive than those from lean mice. In summary, our results reveal alterations in the number and function of tumor infiltrating immune cells in obese mice. RNA-Sequencing of lean vs obese tumors revealed significant changes in pathways related to Hypertrophic and Dilated Cardiomyopathy, Adrenergic signaling in Cardiomyocytes, as well as signaling pathways of Insulin, cGMP-PKG, Glucagon, Calcium and Adipocytokine and others. Our data warrants further investigation on the immunosuppressive tumor microenvironment in obese TNBC patients.

Citation Format: Fokhrul Hossain, Deniz A Ucar, Maria Sanchez-Pino, Matthew Dean, Samarpan Majumder, Dorota Wyczechowska, Giulia Monticone, Rachel Sabol, Keli Xu, Luis D Valle, Jovanny Zabaleta, Bruce Bunnell, Lucio Miele. Investigating tumor infiltrating immune cells signature in obese 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 3866.

ERK5 Is Required for Tumor Growth and Maintenance Through Regulation of the Extracellular Matrix in Triple Negative Breast Cancer

Conventional mitogen-activated protein kinase (MAPK) family members regulate diverse cellular processes involved in tumor initiation and progression, yet the role of ERK5 in cancer biology is not fully understood. Triple-negative breast cancer (TNBC) presents a clinical challenge due to the aggressive nature of the disease and a lack of targeted therapies. ERK5 signaling contributes to drug resistance and metastatic progression through distinct mechanisms, including activation of epithelial-to-mesenchymal transition (EMT). More recently a role for ERK5 in regulation of the extracellular matrix (ECM) has been proposed, and here we investigated the necessity of ERK5 in TNBC tumor formation. Depletion of ERK5 expression using the CRISPR/Cas9 system in MDA-MB-231 and Hs-578T cells resulted in loss of mesenchymal features, as observed through gene expression profile and cell morphology, and suppressed TNBC cell migration. In vivo xenograft experiments revealed ERK5 knockout disrupted tumor growth kinetics, which was restored using high concentration Matrigel™ and ERK5-ko reduced expression of the angiogenesis marker CD31. These findings implicated a role for ERK5 in the extracellular matrix (ECM) and matrix integrity. RNA-sequencing analyses demonstrated downregulation of matrix-associated genes, integrins, and pro-angiogenic factors in ERK5-ko cells. Tissue decellularization combined with cryo-SEM and interrogation of biomechanical properties revealed that ERK5-ko resulted in loss of key ECM fiber alignment and mechanosensing capabilities in breast cancer xenografts compared to parental wild-type cells. In this study, we identified a novel role for ERK5 in tumor growth kinetics through modulation of the ECM and angiogenesis axis in breast cancer.

Abstract C070: Social determinants of health disparities in triple-negative breast cancer in Louisiana

Introduction: Triple-negative breast cancer (TNBC) is an aggressive, heterogeneous subtype of breast cancer. TNBC patients have generally high risk of recurrence and metastasis, and treatment options remain limited, as there are no effective targeted therapies available. In USA, TNBC is diagnosed disproportionately more frequently in African American (AA) women than in European American (EA) women. We set out to investigate the role of social determinants in racial disparities in TNBC.

Methods: TNBC patients diagnosed in Louisiana from 2010-2012 were identified from the Louisiana Tumor Registry. Patients were geocoded to census tract of residence at time of diagnosis. Census tract population and socioeconomic measures were obtained from the US Census American Community Survey. We used multilevel statistical models to analyze the role of neighborhood concentrated disadvantage index (CDI), a robust measure of physical and social environment, in racial disparities in TNBC incidence, stage at diagnosis, and stage-specific survival for the study population. CDI scores were calculated according to the PhenX Toolkit protocol.

Results: We identified 1,216 women with TNBC for the study. Controlling for age, we found that AA women had a 2.21-fold risk of TNBC incidence compared to EA in Louisiana. Results from multivariate analyses indicated that the incidence of TNBC was independent of neighborhood CDI, as was the racial disparity. However, CDI did explain existing racial disparities in both stage at diagnosis and stage-specific survival. The odds of diagnosis at later stages were 42% higher for black women. A single standard deviation increase in CDI increased the hazard of breast cancer-related death by 19%. Overall, our results suggest that the increased incidence of TNBC in black women is independent of CDI, while neighborhood environment has a greater impact than race on the promotion and progression of the disease. The socioeconomic disadvantage experienced by black women coupled with increased biologic risk for TNBC contribute to the large racial disparity in breast cancer mortality in Louisiana. Further research is needed to determine the mechanisms through which social determinants affect the promotion and progression of this disease and guide efforts to improve overall survival.

Citation Format: Fokhrul Hossain, Denise Danos, Aubrey Gilliland, Claudia Leonardi, Tekeda Ferguson, Neal Simonsen, Qingzhao Yu, Om Prakesh, Richard Scribner, Lucio Miele. Social determinants of health disparities in triple-negative breast cancer in Louisiana [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C070.

FRI0438 POST-CHIKUNGUNYA CHRONIC ARTHRITIS - SHARING OF BANGLADESH EXPERIENCE OVER ONE YEAR FOLLOW UP OF 60 PATIENTS

Background:

Chikungunya virus (CHIKV) infection is an emerging disease which is responsible for several epidemics around the world1. Systematic review and meta-analysis had shown that approximately 25% of cases of Chikungunya(CHIK) would develop CHIK-Chronic Inflammatory Rheumatism and 14% would develop persistent arthritis (or spondylitis)2.

Objectives:

To describe the frequency of the clinical patterns of chronic arthritis & to characterize the clinical symptoms in a Bangladeshi cohort of CHIK patients 12months post-infection.

Methods:

In 2017, a Chikungunya outbreak occurred in Dhaka, Bangladesh, during which a prospective cohort of CHIK patients with confirmed diagnosis was constituted. A longitudinal follow up of 60 patients from an initial cohort of 142 patients, attending the out-patient department of Rheumatology, BSMMU, was done. Patients having arthritis/ arthralgia or both lasting more than 3 months were considered as chronic cases. Their baseline and follow-up symptoms at 3m, 6m and 12months were evaluated. Functional status was assessed with the Bengali Version Health Assessment Questionnaire (HAQ).

Results:

Of the initial 142 patients enrolled in the study, 135(95.1%) had CHIKV-IgM and 29(20.4%) had IgG positive. Patients that followed up in-person were predominantly adult (age 43.73 ± 11.09 years) and female 34 (56.7%). The majority of the patients 35 (58.3%) had undifferentiated arthritis. After three months, 8 (16.3%) had oligoarthralgia, 26 (53.1%) had polyarthralgia and 8 (16.3%) had polyarthralgia with oligoarthritis. At the end of one year, 13 (21.7%) patients underwent complete remission. Among the 47 patients, 21 had joint involvement where 11(52.4%) had polyarthralgia, 5(23.8%) had polyarthralgia with oligoarthritis, 5 (23%) had oligoarthralgia and 4 (19%) had monoarthralgia. Among the 47 patients, mild, moderate and severe functional disability was present in 89.4%, 6.4% and 4.3% patients respectively.

Conclusion:

After one year of follow up, one-third of the patients remained symptomatic. Polyarthralgia was the predominant clinical feature. Mild functional disability was also observed in a significant number of patients.

References:

[1]Ali Ou Alla S, Combe B. Arthritis after infection with Chikungunya virus. Best Pract Res Clin Rheumatol. 2011;25(3):337-46.

[2]Rodríguez-Morales AJet al.Prevalence of Post-Chikungunya Infection Chronic Inflammatory Arthritis: A Systematic Review and Meta-Analysis.Arthritis. Care. Res. 68(12), 1849-1858 (2016).

Table 1.

Socio-demographic and clinical pattern of patients with Chronic CHK arthritis (n=60)

Variablesn(%)Age (in years)Mean ±SD43.73 ±11.1SexFemale34 (56.7)Male26 (43.3)First joint involvementGeneralized34 (56.7)Ankle12 (20.0)Knee6 (10.0)Wrist5 (8.3)Others (MTP, shoulder, neck and axial plane)3 (5.0)Clinical patternUndifferentiated35(58.3)Spondyloarthritis10 (16.7)Rheumatoid Arthritis7 (11.7)Pre-existing Spondyloarthritis6(10.2)Pre-existing Rheumatoid Arthritis1(1.7)Pre-existing Osteo-arthritis Arthritis1(1.7)Table 2.

Joint involvement of patients with Chronic CHIK arthritis

Joint characteristics3 m (n=49)6 m (n=36)1yr (n=21)f(%)f(%)f(%)Type of involvement in persistent painJoint only33 (55.0)28 (46.7)20 (33.3)Both joint & soft-tissue16 (26.7)8 (13.3)1 (1.7)Joint involvementMonoarthralgia1 (2.0)5 (13.9)4 (19.0)Oligoarthralgia8 (16.3)6 (16.7)5 (23.0)Polyarthralgia26 (53.1)18 (50.0)11 (52.4)Monoarthritis1 (2.0)0(0.0)0(0.0)Oligoarthritis6 (12.2)3 (8.3)0(0.0)Polyarthritis7 (14.3)9 (11.1)1 (4.8)Oligoarthralgia & monoarthritis1 (2.0)0 (0.0)0 (0.0)Polyarthralgia & monoarthritis0 (0.0)1 (2.8)0 (0.0)Polyarthralgia & oligoarthritis8 (16.3)4 (11.1)5 (23.8)Polyarthralgia & Polyarthritis1 (2.0)0 (0.0)0 (0)

Disclosure of Interests:

None declared

Obesity-Altered Adipose Stem Cells Promote Radiation Resistance of Estrogen Receptor Positive Breast Cancer through Paracrine Signaling

Obesity is associated with poorer responses to chemo- and radiation therapy for breast cancer, which leads to higher mortality rates for obese women who develop breast cancer. Adipose stem cells (ASCs) are an integral stromal component of the tumor microenvironment (TME). In this study, the effects of obesity-altered ASCs (obASCs) on estrogen receptor positive breast cancer cell’s (ER⁺BCCs) response to radiotherapy (RT) were evaluated. We determined that BCCs had a decreased apoptotic index and increased surviving fraction following RT when co-cultured with obASCs compared to lnASCs or non-co-cultured cells. Further, obASCs reduced oxidative stress and induced IL-6 expression in co-cultured BCCs after radiation. obASCs produce increased levels of leptin relative to ASCs from normal-weight individuals (lnASCs). obASCs upregulate the expression of IL-6 compared to non-co-cultured BCCs, but BCCs co-cultured with leptin knockdown obASCs did not upregulate IL-6. The impact of shLeptin obASCs on radiation resistance of ER⁺BCCs demonstrate a decreased radioprotective ability compared to shControl obASCs. Key NOTCH signaling players were enhanced in ER⁺BBCs following co-culture with shCtrl obASCs but not shLep obASCs. This work demonstrates that obesity-altered ASCs, via enhanced secretion of leptin, promote IL-6 and NOTCH signaling pathways in ER⁺BCCs leading to radiation resistance.

Abstract P6-03-17: Effect of histone deacetylase inhibitors on patient-derived neoadjuvant chemotherapy resistant triple negative breast cancer xenografts that represent understudied patients

Triple negative breast cancers (TNBCs) are a clinically and biologically aggressive breast cancer (BC) subtype; TNBC tumors have higher rates of metastasis, relapse and acquired/inherent drug resistance. Incidence and mortality rates of TNBC are stratified based on patient ethnicity - patients with African ancestry have higher mortality rates and diagnoses of invasive cancers compared to patients representing other ethnicities. Louisiana has a high proportion of African-American residents (32.7% in 2018), and New Orleans has among the highest incidences of TNBC in the country. Many of our patients present with TNBC tumors that are partially or completely resistant to neoadjuvant chemotherapies. There are currently no clinically approved targeted therapies for TNBC. Current therapeutic discovery focused TNBC research does not aptly address the knowledge gap regarding ethnic disparity in TNBC incidence/mortality rates and TNBC biology. To date, most TNBC-related research and knowledge has been acquired from Caucasian patients, although patients with African and Hispanic ancestries represent the majority of TNBC cases. Patient-derived xenografts (PDXs) are extensively used in BC research, as they mimic complex microanatomy, oncoarchitecture, and cell-cell/cell-stroma interactions of tumors. Here, we demonstrated the unique composition of PDX tumors is not dramatically affected by serial transplantation in mice, based on molecular phenotypes (examined using qRT-PCR and RNA sequencing) and the oncoarchitecture of the extracellular matrix (based on cryogenic scanning electron microscopy). Using these models in basic research facilitates translation of laboratory findings to the clinical setting, and dramatically enhanced drug discovery research. We have established over twelve TNBC PDX models, 90% of which represent patients of African ancestry, and most of which are resistant to neoadjuvant regimens. We focus on dissecting and evaluating kinase inhibitor/targeted drug response to various individual components (tumor cell biology, stroma, immune, extracellular matrix) of chemotherapy resistant TNBC tumors.

Histone deacetylase inhibitors (DACi) are a promising therapeutic agent in TNBC systems; they have been shown to suppress tumorigenesis and metastasis in TNBC through suppression of the mesenchymal phenotype in cell line-based studies. In this study we utilized various TNBC PDX models (TU-BcX-2K1, -2O0, 4IC, -4M4, -4QAN, -4QX) to assess these findings in more translational systems. Interestingly, we showed that DACi effect on tumorigenesis and metastasis varied depending on specific TNBC PDXs utilized. These data implicate specific genes/signaling pathways exist in individual patient tumors that can predict tumor responsiveness to DACi. Preliminary data using the NCI oncology drug set implicated the MEK1/2 pathway contributed to sensitization of TNBC cells. Furthermore, we found a disconnect in gene expressions that were previously shown to be affected by DACi therapy (CDH1, VIM, ZEB1, ZEB2) in various derivations of PDX models (cells, PDX-Os, ex vivo, in vivo). These findings demonstrate that testing various derivations of PDX models is crucial to parsing out specific mechanisms of targeted therapies. Our methods presented here to assess targeted drug response and drug resistance using PDX models can be applied to any area of cancer research and is not limited to breast cancer.

Citation Format: Margarite Matossian, Steven Elliott, Maryl Wright, Tiffany Chang, Madlin Alzoubi, Henri Wathieu, Rachel Sabol, Alex Alfortish, Hope Burks, Van Hoang, Deniz Ucar, Gabrielle Windsor, Thomas Yan, Jovanny Zabaleta, Fokhrul Hossain, Bruce Bunnell, Krzysztof Moroz, Arnold Zea, Adam Riker, Steven Jones, Elizabeth Martin, Lucio Miele, Bridgette Collins-Burow, Matthew Burow. Effect of histone deacetylase inhibitors on patient-derived neoadjuvant chemotherapy resistant triple negative breast cancer xenografts that represent understudied patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-03-17.

Abstract P5-04-19: Sulindac sulfide as a non-immune suppressive gamma secretase modifier to target triple negative breast cancer

Triple negative breast cancer (TNBC) is defined as pathologically negative for estrogen receptor (ER-), progesterone receptor (PR-), and human epidermal growth factor receptor 2 amplification (HER2-). TNBCs are a heterogeneous group of clinically aggressive cancers with high risk of recurrence and metastasis, and current treatment options remain limited. Immunotherapy with checkpoint inhibitors shows promise. However, recent data show that crosstalk between cancer stem cells (CSC) and the immune microenvironment leads to immunotherapy resistance, while myeloid-derived suppressor cells (MDSC) promote CSC survival via Notch signaling. Strong evidence supports the involvement of Notch, a prominent CSC pathway, in TNBC progression. Expression of Notch1 and its ligand Jagged1 correlate with poor prognosis. Notch inhibitors, Including Gamma Secretase Inhibitors (GSIs) are quite effective in preclinical models of TNBC. However the success of GSIs in clinical trials has been limited by their intestinal toxicity and potential for adverse immunological effects. Our overarching goal is to replace GSIs with agents that lack their systemic toxicity and adverse immunological effects. We identified Sulindac Sulfide (SS), the active metabolite of FDA-approved NSAID Sulindac, as a potential candidate to replace GSIs. We confirmed that SS has Gamma Secretase Modifier (GSM) activity, in addition to cyclo-oxygenase (COX) inhibition. SS inhibits Notch1 cleavage in TNBC cells, but not in murine T-cells. SS significantly inhibited mammospheres growth in all human and murine TNBC models we tested: 1) human MDA-MB-231 cells; 2) murine TNBC model C0321, from targeted conditional knockout of Lunatic Fringe (LFng-/-); and 3) Two TNBC patient-derived xenograft models, 2K1 and 4IC. In C0321 tumors in mice, we found that SS had remarkable single-agent anti-tumor activity and virtually eliminated Notch1 expression in tumors without intestinal toxicity. SS caused an increase in intra-tumoral CD11c+ dendritic cells and CD8 cells. SS did not affect the numbers of tumor infiltrating macrophages or myeloid-derived suppressor cells (MDSC). However, SS blocked the immunosuppressive function of bone marrow-derived MDSC. RNA-Sequencing of SS-treated tumors revealed significant reduction of CXCL14, EGR1, HOXC6, MAGI2, NCAM1, APOE, CLU (a Wnt target), DTX4 (an E3-ligase positive regulator of Notch activation), and TGFB3 genes and upregulation of CCL17, EPCAM, FABP4, C4A, LTF, ZBTB16, INADL, and FGFR2 genes. Importantly, SS enhanced the antitumor effect of a-PDL1 immunotherapy in our 0321 TNBC mouse model. Our data support further investigation of SS for the treatment of TNBC, with standard of care or with immunotherapy. Repurposing an FDA-approved, safe agent for the treatment of TNBC may be significantly easier and more cost-effective than developing unproven investigational agents.

Citation Format: Fokhrul Hossain, Deniz A Ucar, Samarpan Majumder, Margarite Matossian, Giulia Monticone, Keli Xu, Yong Ran, Lisa Minter, Yaguang Xi, Matthew Burow, Todd Golde, Barbara Osborne, Lucio Miele. Sulindac sulfide as a non-immune suppressive gamma secretase modifier to target triple negative breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-04-19.

Synthesis of glycoimmunogen Tn-Thr-PS A1 via hydrazone bond and stability optimization of PS A1 monosaccharide mimics under vaccine development conditions

Previously, our group constructed several immunogens utilizing oxime linkage to conjugate a T-cell stimulatory zwitterionic polysaccharide PS A1 and tumor associated carbohydrate antigens (TACAs) in acetate buffer. Here, a semi-synthetic immunogen was synthesized using hydrazone conjugation between PS A1 and a glycopeptide hydrazide (α-d-GalNAc-l-Thr-NH-NH2) with an excellent loading in PBS buffer. To get robust immune response, the retention of zwitterionic character of PS A1 under vaccine construction conditions is essential. In this regard, the stability of embedded pyruvate acetal moiety in tetrasaccharide repeating unit of PS A1 can validate the retention of the dual charges. Therefore, rather than utilizing this highly immunogenic PS A1 fully, stability studies were performed with synthetic 1-thiophenyl-4,6-O-pyruvate acetal-d-galactopyranose in varying acetate buffer pHs and time intervals. Furthermore, 1-propyl-d-galactofuranose was synthesized to mimick the d-Galf of PS A1 to examine regioselective hydrazone and oxime formation with α-d-GalNAc-l-Thr-NH-NH2 and α-d-GalNAc-ONH2 moieties respectively.

Abstract 3439: Sulindac sulfide as a gamma secretase modifier to target triple negative breast cancer

Triple negative breast cancer (TNBC) is defined as pathologically negative for estrogen receptor (ER-), progesterone receptor (PR-), and human epidermal growth factor receptor 2 amplification (HER2-). TNBCs are a heterogeneous group of clinically aggressive breast cancers with high risk of recurrence and metastasis, but the current treatment options remain limited. There is strong evidence supporting the involvement of Notch signaling in TNBC progression. Expression of Notch1 and its ligand Jagged1 correlate with poor prognosis. Notch inhibitors, Including Gamma Secretase Inhibitors (GSIs) are quite effective in preclinical models of TNBC. However the success of GSIs in clinical trials is limited by their intestinal toxicity and adverse immunological effects. Our overarching goal is to replace GSIs with agents that lack their systemic toxicity and adverse immunological effects. We identified Sulindac Sulfide (SS), the active metabolite of FDA-approved NSAID Sulindac, as a potential candidate to replace GSIs. SS has documented Gamma Secretase Modifier (GSM) activity, in addition to cyclo-oxygenase (COX) inhibition. We confirmed that SS inhibits Notch1 cleavage in TNBC cells, but not in murine T-cells. SS significantly inhibited mammospheres growth in all human and murine TNBC models we tested: 1) human MDA-MB-231 cells; 2) murine TNBC model C0321, from targeted conditional knockout of Lunatic Fringe (LFng-/-); and 3) Two TNBC patient-derived xenograft models, 2K1 and 4IC. In C0321 tumors, we found that SS had remarkable single-agent anti-tumor activity and virtually eliminated Notch1 expression in tumors. SS caused an increase in intra-tumoral CD11c+ dendritic cells, but decreased CD4 cells, which in this model are largely PD-1 positive (exhausted). CD8 cells were modestly increased. SS did not affect the numbers of tumor infiltrating macrophages or myeloid-derived suppressor cells (MDSC). However, SS blocked the immunosuppressive function of bone marrow-derived MDSC. RNA-Sequencing of SS-treated tumors revealed significant reduction of CXCL14, EGR1, HOXC6, MAGI2, NCAM1, APOE, CLU (a Wnt target), DTX4 (an E3-ligase positive regulator of Notch activation), and TGFB3 genes and upregulation of CCL17, EPCAM, FABP4, C4A, LTF, ZBTB16, INADL, and FGFR2 genes. Our data support further investigation of SS for the treatment of TNBC, with standard of care or with immunotherapy. Repurposing an FDA-approved, safe agent for the treatment of TNBC may be significantly easier and more cost-effective than developing unproven investigational agents.

Citation Format: Fokhrul Hossain, Deniz A Ucar, Samarpan Majumder, Margarite Matossian, Keli Xu, Yong Ran, Lisa Minter, Yaguang Xi, Matthew Burow, Todd Golde, Barbara Osborne, Lucio Miele. Sulindac sulfide as a gamma secretase modifier to target triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3439.

Gene shaving using a sensitivity analysis of kernel based machine learning approach, with applications to cancer data

BACKGROUND

Gene shaving (GS) is an essential and challenging tools for biomedical researchers due to the large number of genes in human genome and the complex nature of biological networks. Most GS methods are not applicable to non-linear and multi-view data sets. While the kernel based methods can overcome these problems, a well-founded positive definite kernel based GS method has yet to be proposed for biomedical data analysis.

METHODS AND FINDINGS

Since the kernel based methods on genomic information can improve the prediction of diseases, here we proposed a noble method, "kernel based gene shaving" which is based on the influence function of kernel canonical correlation analysis. To investigate the performance of the proposed method in comparison to state-of-the-art-method in gene saving, we analyzed extensive simulated and real microarray gene expression data set. The performance metrics including true positive rate, true negative rate, false positive rate, false negative rate, misclassification error rate, the false discovery rate and area under curves were computed for each methods. In colon cancer data analysis, the proposed method identified a significant subsets of 210 genes out of 2000 genes and suggestive superior performance compared with other methods. The proposed method can be applied to the study of other disease process where two view data is a common task.

CONCLUSIONS

We addressed the challenge of finding unique kernel based GS methods by using the influence function of kernel canonical correlation analysis. The proposed method has shown to have better performance than state-of-the-art-methods in gene saving and has identified many more significant gene interactions, suggesting that genes function in a concerted effort in colon cancer. In similar biomedical data analysis, kernel based methods could be applied to select a potential subset of genes. The positive definite kernel based methods can overcome the non-linearity problem and improve the prediction process.

Neighborhood Social Determinants of Triple Negative Breast Cancer

Triple Negative Breast Cancer (TNBC) is an aggressive, heterogeneous subtype of breast cancer, which is more frequently diagnosed in African American (AA) women than in European American (EA) women. The purpose of this study is to investigate the role of social determinants in racial disparities in TNBC. Data on Louisiana TNBC patients diagnosed in 2010–2012 were collected and geocoded to census tract of residence at diagnosis by the Louisiana Tumor Registry. Using multilevel statistical models, we analyzed the role of neighborhood concentrated disadvantage index (CDI), a robust measure of physical and social environment, in racial disparities in TNBC incidence, stage at diagnosis, and stage-specific survival for the study population. Controlling for age, we found that AA women had a 2.21 times the incidence of TNBC incidence compared to EA women. Interestingly, the incidence of TNBC was independent of neighborhood CDI and adjusting for neighborhood environment did not impact the observed racial disparity. AA women were more likely to be diagnosed at later stages and CDI was associated with more advanced stages of TNBC at diagnosis. CDI was also significantly associated with poorer stage-specific survival. Overall, our results suggest that neighborhood disadvantage contributes to racial disparities in stage at diagnosis and survival among TNBC patients, but not to disparities in incidence of the disease. Further research is needed to determine the mechanisms through which social determinants affect the promotion and progression of this disease and guide efforts to improve overall survival.

Abstract P4-07-05: A novel, first in class Notch transcriptional inhibitor, CB-103 has activity on luminal breast cancer stem cells in combination with fulvestrant

The Notch signaling pathway plays a central role in cellular differentiation, growth and stem cell maintenance. Expression and activation of Notch pathway receptors and ligands have differential outcomes depending on the tissue, localization and cell type. When Notch pathway is aberrantly activated by genetic lesions, it can be a major driver for Notch-dependent cancers and can cause resistance to standard of care treatment. We and others have shown that in Estrogen Receptor (ER)-positive breast cancers, estrogen deprivation caused by endocrine therapy results in Notch1 and Notch4 activation. In turn, Notch1 stimulated ER-dependent transcription in the absence of estrogen, causing endocrine resistance. Combinations of Notch inhibitors and endocrine therapy are effective in preclinical models of ER-positive breast cancer and have shown promising signals in early clinical trials.

Cellestia's lead development candidate CB-103 is a small molecule, first-in-class, oral pan-Notch inhibitor. CB-103 selectively blocks Notch pathway activation-related gene transcription through binding to a Notch specific protein in the transcription factor complex. The blockade occurs by protein-protein interaction inhibition with a binding site critical for the assembly of the Notch transcription complex. This is a unique mode of action, which allows blocking Notch signaling regardless of the genetic lesions which have activated the pathway.

We have performed mammosphere assays to test the potency and efficacy of this compound on stem cell ability to form sphere. We used two different doses of CB-103; either alone or in combination with a fixed dose of Fulvestrant (30nM), a SERD, in our mammosphere assays. Two different ER+ luminal,endocrine resistant cell lines were tested and compared with their parental controls. From our data, it's apparent that there is a synergistic effect when using CB-103 in combination with Fulvestrant. It's also evident that the efficacy of CB-103 is maximal maximizes at the lowest concentration tested in our assays. The combination was effective in 3 out of 4 models. However, the effect of CB-103 on MCF7-TAMR either as a single agent or in combination was not statistically significant.

Cellestia has received regulatory approval to start clinical development with CB-103 in a first-in-human study Phase l – lla study investigating safety (Ph l) and preliminary single agent efficacy (Ph lla) of CB-103 in patients with advanced solid cancers and haematological malignancies. Our data support the notion of testing this agent in ER-positive breast cancer in combination with SERDs.

Citation Format: Majumder S, Crabtree J, Hossain F, Murone M, Lehal R, Miele L. A novel, first in class Notch transcriptional inhibitor, CB-103 has activity on luminal breast cancer stem cells in combination with fulvestrant [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-07-05.

Abstract P6-22-01: Repurposing sulindac sulfide as a notch inhibitor to target cancer stem-like cells in triple negative breast cancer

Triple negative breast cancer (TNBC) is a heterogeneous group of clinically aggressive breast cancers. TNBC patients have a high risk of recurrence and metastasis, and current treatment options remain limited. There is strong evidence supporting the involvement of Notch signaling in TNBC progression. Expression of Notch1 and its ligand Jagged1 correlate with poor prognosis. Emerging evidence suggests that cancer stem-like cells (CSCs) that escape chemo or radiation therapy in TNBC are often Notch-dependent. At the same time, there is evidence that active tumor immunity predicts good response to neo-adjuvant chemotherapy in TNBC. Notch inhibitors, including Gamma Secretase Inhibitors (GSIs) are quite effective in preclinical models of TNBC, where they eliminate CSCs resistant to chemotherapy. However, the success of GSIs in clinical trials is limited by their intestinal toxicity and adverse immunological effects. CD4 and CD8 T-cells, necessary to adaptive tumor immunity, require Notch1 for activation. Our overarching goal is to replace GSIs with agents that lack their systemic toxicity and adverse immunological effects. We identified Sulindac Sulfide (SS), the active metabolite of FDA-approved NSAID Sulindac, as a potential candidate to replace GSI. SS has Gamma Secretase Modifier (GSM) activity. We confirmed that SS inhibits Notch1 cleavage in TNBC cells. SS significantly inhibited mammosphere growth in all human and murine TNBC models we tested: 1) human MDA-MB-231 cells; 2) murine TNBC model C0321, from targeted conditional knockout of Lunatic Fringe (LFng-/-); and 3) Two TNBC patient-derived xenograft models, 2K1 and 4IC. In contrast, SS did not inhibit Notch expression or cleavage in murine T cells. In C0321 tumors, which recapitulate human mesenchymal TNBC, we found that SS had remarkable single-agent anti-tumor activity and virtually eliminated Notch1 expression in tumors. SS caused an increase in intra-tumoral CD11c+ dendritic cells, but decreased CD4 cells, which in this model are largely PD-1 positive (exhausted). CD8 cells were modestly increased. SS did not affect the number of tumor infiltrating macrophages or myeloid-derived suppressor cells (MDSC). However, SS blocked the immunosuppressive function of bone marrow-derived MDSC. We are currently investigating the mechanisms of this anti-tumor activity. Our data support further investigation of SS for the treatment of TNBC, with standard of care or with immunotherapy agents. Repurposing an FDA-approved, safe agent for the treatment of TNBC would be significantly easier and more cost-effective than developing unproven investigational agents.

Citation Format: Hossain F, Ucar D, Majumder S, Xu K, Ran Y, Minter L, Xi Y, Burow M, Golde T, Osborne B, Miele L. Repurposing sulindac sulfide as a notch inhibitor to target cancer stem-like cells in triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-22-01.

Adenosine A2A Receptor Stimulation Inhibits TCR-Induced Notch1 Activation in CD8+T-Cells

Notch receptors signaling is required for optimal T-cell activation and function. T-cell receptor (TCR) engagement can activate Notch receptors in T-cells in a ligand-independent fashion. In this study, we examined the role of adenosine A2A receptor (A2AR) signaling pathway in regulating the activity of Notch1 induced by TCR stimulation in CD8+T-cells. A selective A2AR agonist decreased Notch1 protein expression and Notch1 cleavage, and reduced transcripts of Notch1-target genes Hes1 and Myc in activated CD8+T-cells. Inhibition of TCR-induced Notch1 expression by an A2AR agonist was accompanied by increased cAMP concentration and mimicked by forskolin. This effect was associated with reduced IFN-γ and granzyme B production. The effect of an A2AR agonist was abrogated by a selective A2AR antagonist and absent in CD8+T-cells harvested from A2AR-/- mice. Stimulation of A2AR reduced Notch1 receptor levels by inhibiting upstream TCR signals, including ZAP70 phosphorylation, in turn impairing the generation of the active Notch1 intracellular domain (N1ICD). Direct activation of PKC with PMA and ionomycin bypassed A2AR-induced Notch1 inhibition. Overexpression of N1ICD in CD8+T-cells prevented the suppressive effects of an A2AR agonist on proliferation and cytokine release during activation. Our results identify the A2AR signaling pathway as an important regulator of TCR-induced Notch1 receptor activation in CD8+T-cells, and Notch as an important target of the immune suppressive effects of A2AR. We propose a mechanism whereby A2AR impairs CD8 T-cells function through inhibition of Notch1 receptor activation.

Notch Signaling Regulates Mitochondrial Metabolism and NF-κB Activity in Triple-Negative Breast Cancer Cells via IKKα-Dependent Non-canonical Pathways

Triple negative breast cancer (TNBC) patients have high risk of recurrence and metastasis, and current treatment options remain limited. Cancer stem-like cells (CSCs) have been linked to cancer initiation, progression and chemotherapy resistance. Notch signaling is a key pathway regulating TNBC CSC survival. Treatment of TNBC with PI3K or mTORC1/2 inhibitors results in drug-resistant, Notch-dependent CSC. However, downstream mechanisms and potentially druggable Notch effectors in TNBC CSCs are largely unknown. We studied the role of the AKT pathway and mitochondrial metabolism downstream of Notch signaling in TNBC CSC from cell lines representative of different TNBC molecular subtypes as well as a novel patient-derived model. We demonstrate that exposure of TNBC cells to recombinant Notch ligand Jagged1 leads to rapid AKT phosphorylation in a Notch1-dependent but RBP-Jκ independent fashion. This requires mTOR and IKKα. Jagged1 also stimulates mitochondrial respiration and fermentation in an AKT- and IKK-dependent fashion. Notch1 co-localizes with mitochondria in TNBC cells. Pharmacological inhibition of Notch cleavage by gamma secretase inhibitor PF-03084014 in combination with AKT inhibitor MK-2206 or IKK-targeted NF-κB inhibitor Bay11-7082 blocks secondary mammosphere formation from sorted CD90^hi or CD44⁺CD24^low (CSCs) cells. A TNBC patient-derived model gave comparable results. Besides mitochondrial oxidative metabolism, Jagged1 also triggers nuclear, NF-κB-dependent transcription of anti-apoptotic gene cIAP-2. This requires recruitment of Notch1, IKKα and NF-κB to the cIAP-2 promoter. Our observations support a model where Jagged1 triggers IKKα-dependent, mitochondrial and nuclear Notch1 signals that stimulate AKT phosphorylation, oxidative metabolism and transcription of survival genes in PTEN wild-type TNBC cells. These data suggest that combination treatments targeting the intersection of the Notch, AKT and NF-κB pathways have potential therapeutic applications against CSCs in TNBC cases with Notch1 and wild-type PTEN expression.

Abstract 157: Targeting cancer stem-like cells in triple negative breast cancer

Triple Negative Breast Cancer (TNBC), an aggressive, heterogeneous subtype of breast cancer, and immunohistochemically negative for estrogen receptor α (ER-), progesterone receptor (PR-), and lacking amplification of the human epidermal growth factor receptor 2 locus (HER2-). TNBC patients have high risk of recurrence and metastasis, and current treatment options remain limited. Cancer stem-like cells (CSCs) have been linked to cancer initiation, progression and chemotherapy resistance. Therefore CSC-targeted therapies are keenly sought. There is strong evidence for the involvement of Notch signaling in TNBC. Notch1 is highly expressed in Basal-like 1 (BL1) and especially Mesenchymal-Stem-Like (MSL) TNBCs. Expression of Notch1 and its ligand Jagged1 correlates with poor prognosis. Moreover, strong evidence supports key roles of different Notch paralogs in breast CSCs. Moreover the role of non-canonical Notch signaling in TNBC remains unknown. Here, we demonstrate that Notch1 promotes cell survival in MDA-MB-231 cells, representative of MSL TNBC, in part by activating NF-κB. Notch activation by Jagged1-expressing stromal cells enhances transcription of the anti-apoptotic gene cIAP-2 (BIRC3), a known NF-κB target. This event is dependent on recruitment of NF-κB subunits, IKKα and Notch1 to the cIAP-2 promoter. Short term exposure of MDA-MB-231 cells (MSL, PTEN wild-type), but not MDA-MB-468 cells (BL1, PTEN-null) to recombinant Jagged1 leads to AKT phosphorylation. This is suppressed by dual mTORC1/2 inhibitors, AKT inhibitors and IKKα inhibitors but not Everolimus (mTORC1-selective inhibitor). These observations support a model where canonical and non-canonical mechanisms downstream of Notch1 trigger AKT phosphorylation and NF-κB activation in PTEN wild type TNBC cells. This suggests a bidirectional crosstalk between the IKKα and AKT arms of this Jagged1-activated pathway. We also demonstrate that recombinant Jagged1 increases the cellular metabolism of TNBC cells and knockdown of Notch1 or IKKα by siRNA decreases mitochondrial respiration and glycolysis. We have found that CSCs derived from MDA-MB-231 cells have increased Notch1, p-AKT, and mitochondrial respiration. AKT inhibition or NF-κB inhibition decreases both mitochondrial respiration and glycolysis of TNBC derived CSCs. Pharmacological inhibition of Notch cleavage by gamma secretase inhibitor (PF-03084014) in combination with AKT inhibitor (MK-2206) or NF-κB inhibitor (Bay11-7082) blocks CD90hi or CD44+CD24low sorted secondary mammospheres formation. These data suggest that combination treatments affecting Notch, NF-kB or AKT pathways have potential therapeutic importance in targeting CSCs of TNBC.

Citation Format: Fokhrul Hossain, Ayse D Ucar Bilyeu, Claudia Sorrentino, Judy Crabtree, Antonio Pannuti, Margarite Matossian, Matthew Burow, Todd Golde, Barbara Osborne, Lucio Miele. Targeting cancer stem-like cells in triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 157.

Notch Signaling in Myeloid Cells as a Regulator of Tumor Immune Responses

Cancer immunotherapy, which stimulates or augments host immune responses to treat malignancies, is the latest development in the rapidly advancing field of cancer immunology. The basic principles of immunotherapies are either to enhance the functions of specific components of the immune system or to neutralize immune-suppressive signals produced by cancer cells or tumor microenvironment cells. When successful, these approaches translate into long-term survival for patients. However, durable responses are only seen in a subset of patients and so far, only in some cancer types. As for other cancer treatments, resistance to immunotherapy can also develop. Numerous research groups are trying to understand why immunotherapy is effective in some patients but not others and to develop strategies to enhance the effectiveness of immunotherapy. The Notch signaling pathway is involved in many aspects of tumor biology, from angiogenesis to cancer stem cell maintenance to tumor immunity. The role of Notch in the development and modulation of the immune response is complex, involving an intricate crosstalk between antigen-presenting cells, T-cell subpopulations, cancer cells, and other components of the tumor microenvironment. Elegant studies have shown that Notch is a central mediator of tumor-induced T-cell anergy and that activation of Notch1 in CD8 T-cells enhances cancer immunotherapy. Tumor-infiltrating myeloid cells, including myeloid-derived suppressor cells, altered dendritic cells, and tumor-associated macrophages along with regulatory T cells, are major obstacles to the development of successful cancer immunotherapies. In this article, we focus on the roles of Notch signaling in modulating tumor-infiltrating myeloid cells and discuss implications for therapeutic strategies that modulate Notch signaling to enhance cancer immunotherapy.

γ-Secretase inhibitors in cancer clinical trials are pharmacologically and functionally distinct

γ-Secretase inhibitors (GSIs) are being actively repurposed as cancer therapeutics based on the premise that inhibition of NOTCH1 signaling in select cancers is therapeutic. Using novel assays to probe effects of GSIs against a broader panel of substrates, we demonstrate that clinical GSIs are pharmacologically distinct. GSIs show differential profiles of inhibition of the various NOTCH substrates, with some enhancing cleavage of other NOTCH substrates at concentrations where NOTCH1 cleavage is inhibited. Several GSIs are also potent inhibitors of select signal peptide peptidase (SPP/SPPL) family members. Extending these findings to mammosphere inhibition assays in triple-negative breast cancer lines, we establish that these GSIs have different functional effects. We also demonstrate that the processive γ-secretase cleavage pattern established for amyloid precursor protein (APP) occurs in multiple substrates and that potentiation of γ-secretase cleavage is attributable to a direct action of low concentrations of GSIs on γ-secretase. Such data definitively demonstrate that the clinical GSIs are not biological equivalents, and provide an important framework to evaluate results from ongoing and completed human trials with these compounds.

Abstract P6-07-06: Targeting cancer stem-like cells metabolism via non-canonical notch signaling pathways in triple negative breast cancer

Triple negative breast cancer (TNBC) is a heterogeneous group of clinically aggressive diseases. TNBC patients have high risk of recurrence and metastasis, and current treatment options remain limited. Cancer stem-like cells (CSCs) have been linked to cancer initiation, progression and chemotherapy resistance. Therefore CSC-targeted therapies are keenly sought. There is strong evidence for the involvement of Notch signaling in TNBC. Notch1 is highly expressed in Basal-like 1 (BL1) and especially Mesenchymal-Stem-Like (MSL) TNBCs. Expression of Notch1 and its ligand Jagged1 correlate with poor prognosis. Moreover, strong evidence supports key roles of different Notch paralogs in breast CSCs. Here, we demonstrate that Notch activation by Jagged1-expressing stromal cells enhances transcription of the anti-apoptotic gene cIAP-2 (BIRC3), a known NF-κB target. This event is dependent on recruitment to the cIAP-2 promoter of NF-κB subunits, IKKα and Notch1. Short term exposure of MDA-MB-231 cells (MSL, PTEN wild-type), but not MDA-MB-468 cells (BL1, PTEN-null) to recombinant Jagged1 leads to AKT phosphorylation. This is suppressed by AKT inhibitors, IKK inhibitors, and dual mTORC1/2 inhibitors but not an mTORC1-selective inhibitor. These observations support a model where canonical and non-canonical mechanisms downstream of Notch1 trigger AKT phosphorylation and NF-κB activation in PTEN wild type TNBC cells. Rapid AKT phosphorylation downstream of Notch1 requires mTORC2, PI3K and IKKα, and contributes to NF-κB activation. This suggests a bidirectional crosstalk between the IKKα and AKT arms of this Jagged1-activated pathway. Importantly, we find co-localization of Notch1 with Mitochondria in MDA-MB-231 cells by confocal microscopy and Western blot of isolated mitochondrial fractions. We demonstrate that recombinant Jagged1 increases metabolism of TNBC cells. Knockdown of Notch1 or IKKα by siRNA decreases mitochondrial respiration and glycolysis. CSCs derived from MDA-MB-231 cells have increased Notch1, p-AKT, and oxidative metabolism compared to non-stem cells. AKT inhibition or IKK inhibition decreases both mitochondrial respiration and glycolysis of TNBC derived CSCs. Pharmacological inhibition of Notch cleavage by gamma secretase inhibitor (PF-03084014) in combination with AKT inhibitor (MK-2206) or IKK inhibitor (Bay11-7082) blocks CD90hi or CD44+CD24low sorted secondary mammospheres formation. Notably, we find similar results in TNBC patient derived xenograft (PDX) models. These data suggest that combination treatments affecting the intersection of Notch, NF-kB and AKT pathways have potential therapeutic importance in targeting CSCs in TNBC cases with high Notch1 expression.

Citation Format: Hossain F, Sorrentino C, Ucar Bilyeu AD, Matossian M, Crabtree J, Pannuti A, Burow M, Golde T, Osborne B, Miele L. Targeting cancer stem-like cells metabolism via non-canonical notch signaling pathways in triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-07-06.

Contamination and ecological risk assessment of trace elements in sediments of the rivers of Sundarban mangrove forest, Bangladesh

In this study, total concentrations of 16 trace elements (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Sb, Hg, Pb, Th and U) in sediments of the rivers of the Sundarban mangrove forest, after the catastrophic oil spill accident in the Sela river of Sundarban, were determined. The overall mean concentrations of V, Cr, Fe and Cd in surface sediments of the Sundarban are remarkably higher than available literature data of those elements. Trace element contamination assessment, using different environmental contamination indices, reveals that As, Sb, Th and U are low to moderately contaminated while Cd is moderately to severely contaminated in the sediments of this area. The multivariate statistical analyses were applied to reveal the origin and behavior of the elements during their transport in the mangrove ecosystem. High Cr, Ni, Cu and As concentrations suggest the risk of potentially adverse biological effects in the ecosystem.

Abstract 2904: Targeting cancer stem-like cells in triple negative breast cancer cells through non-canonical notch signaling

Triple negative breast cancer (TNBC) is a heterogeneous group of clinically aggressive diseases. TNBC patients have high risk of recurrence and metastasis, and current treatment options remain limited. Cancer stem-like cells (CSCs) have been linked to cancer initiation, progression and chemotherapy resistance. Therefore CSC-targeted therapies are keenly sought. There is strong evidence for the involvement of Notch signaling in TNBC. Notch1 is highly expressed in Basal-like 1 (BL1) and especially Mesenchymal-Stem-Like (MSL) TNBCs. Expression of Notch1 and its ligand Jagged1 correlate with poor prognosis. Moreover, strong evidence supports key roles of different Notch paralogs in breast CSCs. Here, we demonstrate that Notch1 promotes cell survival in MDA-MB-231 cells, representative of MSL TNBC, in part by activating NF-κB. Notch activation by Jagged1-expressing stromal cells enhances transcription of the anti-apoptotic gene cIAP-2 (BIRC3), a known NF-κB target. This event is dependent on recruitment to the cIAP-2 promoter of NF-κB subunits, IKKα and Notch1. Short term exposure of MDA-MB-231 cells (MSL, PTEN wild-type), but not MDA-MB-468 cells (BL1, PTEN-null) to recombinant Jagged1 leads to AKT phosphorylation. This is suppressed by dual mTORC1/2 inhibitors, AKT inhibitors and IKKα inhibitors but not Everolimus (mTORC1-selective inhibitor). These observations support a model where canonical and non-canonical mechanisms downstream of Notch1 trigger AKT phosphorylation and NF-κB activation in PTEN wild type TNBC cells. Rapid AKT phosphorylation downstream of Notch1 requires mTORC2, PI3K and IKKα, and contributes to NF-κB activation. This suggests a bidirectional crosstalk between the IKKα and AKT arms of this Jagged1-activated pathway. We demonstrate that recombinant Jagged1 increases the cellular metabolism of TNBC cells and knockdown of Notch1 or IKKα by siRNA decreases mitochondrial respiration and glycolysis. We have found that CSCs derived from MDA-MB-231 cells have increased Notch1, p-AKT, and oxidative metabolism. AKT inhibition or IKKα inhibition decreases both mitochondrial respiration and glycolysis of TNBC derived CSCs. Pharmacological inhibition of Notch cleavage by gamma secretase inhibitor (PF-03084014) in combination with AKT inhibitor (MK-2206) or NF-κB inhibitor (Bay11-7082) blocks CD90hi or CD44+CD24low sorted secondary mammospheres formation. These data suggest that combination treatments affecting Notch, NF-kB and AKT pathways have potential therapeutic importance in targeting CSCs of TNBC cases with wild type PTEN and high Notch1 expression.

Note: This abstract was not presented at the meeting.

Citation Format: Fokhrul Hossain, Claudia Sorrentino, Ayse Bilyeu, Judy Crabtree, Antonio Pannuti, Todd Golde, Barbara Osborne, Lucio Miele. Targeting cancer stem-like cells in triple negative breast cancer cells through non-canonical notch signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2904. doi:10.1158/1538-7445.AM2017-2904

Exogenous lipid uptake induces metabolic and functional reprogramming of tumor-associated myeloid-derived suppressor cells

Myeloid-derived suppressor cells (MDSC) promote tumor growth by blocking anti-tumor T cell responses. Recent reports show that MDSC increase fatty acid uptake and fatty acid oxidation (FAO) to support their immunosuppressive functions. Inhibition of FAO promoted a therapeutic T cell-mediated anti-tumor effect. Here, we sought to determine the mechanisms by which tumor-infiltrating MDSC increase the uptake of exogenous lipids and undergo metabolic and functional reprogramming to become highly immunosuppressive cells. The results showed that tumor-derived cytokines (G-CSF and GM-CSF) and the subsequent signaling through STAT3 and STAT5 induce the expression of lipid transport receptors with the resulting increase in the uptake of lipids present at high concentrations in the tumor microenvironment. The intracellular accumulation of lipids increases the oxidative metabolism and activates the immunosuppressive mechanisms. Inhibition of STAT3 or STAT5 signaling or genetic depletion of the fatty acid translocase CD36 inhibits the activation of oxidative metabolism and the induction of immunosuppressive function in tumor-infiltrating MDSC and results in a CD8⁺ T cell-dependent delay in tumor growth. Of note, human tumor-infiltrating and peripheral blood MDSC also upregulate the expression of lipid transport proteins, and lipids promote the generation of highly suppressive human MDSC in vitro. Our data therefore provide a mechanism by which tumor-derived factors and the high lipid content in the tumor microenvironment can cause the profound metabolic and functional changes found in MDSC and suggest novel approaches to prevent or reverse these processes. These results could further enhance the efficacy of cancer immunotherapy.

Early performance-based and patient-reported outcomes of a contemporary taper fit bone-conserving short stem femoral component in total hip arthroplasty

Aims

The aim of this study was to compare early functional and health related quality of life outcomes (HRQoL) in patients who have undergone total hip arthroplasty (THA) using a bone conserving short stem femoral component and those in whom a conventional length uncemented component was used. Outcome was assessed using a validated performance based outcome instrument as well as patient reported outcome measures (PROMs).

Patients and Methods

We prospectively analysed 33 patients whose THA involved a contemporary proximally porous coated tapered short stem femoral component and 53 patients with a standard conventional femoral component, at a minimum follow-up of two years. The mean follow-up was 31.4 months (24 to 39). Patients with poor proximal femoral bone quality were excluded. The mean age of the patients was 66.6 years (59 to 77) and the mean body mass index was 30.2 kg/m2 (24.1 to 41.0). Outcome was assessed using the Oxford Hip Score (OHS) and the University College Hospital (UCH) hip score which is a validated performance based instrument. HRQoL was assessed using the EuroQol 5D (EQ-5D).

Results

There were no major peri-operative complications. There was no difference in the mean post-operative OHS, EQ-5D or function subscale of the UCH hip scores between the two groups. The mean pre-operative OHS and EQ-5D scores improved significantly (all p <  0.001). The mean functional component of the UCH hip score at final follow-up was 42.5 and 40.6 in the short stem and conventional stem groups, respectively. There was no statistically significant difference between the groups (p = 0.42). A total of seven patients (21.2%) in the short stem group and nine (16.98%) in the conventional group achieved a ceiling effect using the OHS; none did using the function subscale of the UCH hip score.

Conclusion

The proximally porous coated tapered short stem femoral component achieves comparable short-term functional outcomes when compared with a conventional longer stem uncemented femoral component when THA is undertaken in patients with good bone quality. Cite this article: Bone Joint J 2017;99-B(4 Supple B):49–55.

Abstract P5-07-06: A novel non-canonical Notch1-IKKα-mTORC2-AKT pathway maintains survival in triple negative breast cancer cells and cancer stem-like cells

Triple negative breast cancer (TNBC) is a heterogeneous group of clinically aggressive breast cancers. TNBC patients have high risk of recurrence and metastasis, and current treatment options remain limited. There is strong evidence for the involvement of Notch signaling in TNBC and in breast cancer stem-like cells (CSCs). Notch1 is highly expressed in Basal-like 1 (BL1) and especially Mesenchymal-Stem-Like (MSL) TNBCs. Expression of Notch1 and its ligand Jagged1 correlate with poor prognosis. Treatment of TNBC with dual mTORC1/2 inhibitors leads to resistance through activation of Notch1. Expression of Notch1 protein correlates with pAKT and nuclear NF-κB in TNBC. Here, we demonstrate that Notch1 promotes cell survival in MDA-MB-231 cells, representative of MSL TNBC, in part by activating NF-κB. Notch activation by Jagged1-expressing stromal cells enhances transcription of the anti-apoptotic gene cIAP-2 (BIRC3), a known NF-κB target. This event is dependent on recruitment to the cIAP-2 promoter of NF-κB subunits, IKKα and Notch1. Short term exposure of MDA-MB-231 cells (MSL, PTEN wild-type), but not MDA-MB-468 cells (BL1, PTEN-null) to recombinant Jagged1 leads to rapid AKT phosphorylation. This is suppressed by dual mTORC1/2 inhibitors, AKT inhibitors and IKKα inhibitors but not Everolimus (mTORC1-selective inhibitor). Rapid AKT phosphorylation downstream of Notch1 requires mTORC2, PI3K and IKKα, and contributes to NF-κB activation. These observations support a model where canonical and non-canonical mechanisms downstream of Notch1 trigger rapid AKT phosphorylation and NF-κB activation in PTEN wild-type TNBC cells. Both arms of this pathway require IKKα. CSCs derived from MDA-MB-231 cells have increased Notch1, pAKT and pIKKα expression. Combined pharmacological inhibition of Notch and AKT or Notch and IKKα completely blocks secondary mammosphere formation. These data and published literature suggest that: 1) IKKα connects the Notch and mTORC2/AKT pathways in some TNBC subtypes; 2) IKKα is also required for nuclear Notch1-mediated NF-kB activation and may be a critical node in the Notch signaling network; 3) A feedback mechanism may exist in some TNBC cells between mTORC2/AKT and Notch1; 4) The non-canonical Notch-IKKα-AKT pathway has a potential therapeutic role in targeting CSCs of selected TNBC subtypes.

Citation Format: Hossain F, Peng Y, Pannuti A, Backus K, Golde T, Osborne B, Miele L. A novel non-canonical Notch1-IKKα-mTORC2-AKT pathway maintains survival in triple negative breast cancer cells and cancer stem-like cells [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-07-06.

Outcome of intraoperative use of mitomycin C combined with conjunctival auto graft in recurrent pterygium

Background and objectives: Recurrent pterygium is an important ocular problem in our country. There are different modalities of treatment for recurrent pterygium. The present study was undertaken to determine the effect of intraoperative mitomycin C along with conjunctival auto graft to prevent recurrence of pterygium.Methods: Patients with recurrent pterygium attending a tertiary care hospital in Dhaka from January 2013 to June 2015 were included in the study. Cases were randomized into two groups. Group 1 had pterygium surgery with conjunctival auto graft and Group 2 had auto graft and intraoperative mitomycin C (0.02%). All cases were followed up for one year to assess recurrence of pterygium.Results: A total of 54 recurrent pterygia cases were included in the study. The age of study population was 25 to 65 years. The recurrence rate of pterygium after 12 months was 77.7% in group 1 and none in group 2. No major postoperative complication was observed.Conclusion: The study demonstrated that the use of intraoperative mitomycin C along with conjunctival auto graft had significant effect in preventing the recurrence of pterygium.IMC J Med Sci 2016; 10(2): 49-52

Abstract LB-271: Targeting fatty acid metabolism regulates the immunosuppressive activity of myeloid-derived suppressor cells

Myeloid-derived suppressor cells (MDSC) play a major role in the immune defects associated with cancer. Although several mechanisms have been suggested as critical for MDSC-induced T cell suppression, there are no current therapies to block the accumulation and/or function of MDSC. Recent studies have highlighted the role of specific energy metabolic pathways in the activation and function of immune cells. However, the metabolic programs of tumor-associated MDSC (T-MDSC) remain unknown. Herein, we found that T-MDSC, but not splenic MDSC or normal myeloid cells, activated fatty acid oxidation (FAO). T-MDSC increased mitochondrial mass and function, key FAO enzymes, and oxygen consumption rate. Of interest, Inhibition of FAO blocked the immunosuppressive mechanisms and functions in T-MDSC and decreased their production of immunosuppressive cytokines. FAO inhibition also resulted in a T cell-dependent decrease in tumor growth and synergized with low-dose chemotherapy and cellular immunotherapy. Furthermore, targeting fatty acid uptake decreased the regulatory activity of T-MDSC. Human MDSC exhibited similar metabolic characteristics. These data support the possibility of targeting fatty acid metabolism as a novel approach to block MDSC and enhance cancer therapy.

Citation Format: Amir A. Al-Khami, Fokhrul Hossain, Dorota Wyczechowska, Liqin Zheng, Paulo Rodriguez, Augusto C. Ochoa. Targeting fatty acid metabolism regulates the immunosuppressive activity of myeloid-derived suppressor cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-271.

Abstract 4616: A novel non-canonical Notch-AKT- NF-κB pathways in triple negative breast cancer cells

Triple negative breast cancer (TNBC) is a heterogeneous group of clinically aggressive diseases that account for approximately 15-20% of invasive breast cancers. TNBC patients have high risk of recurrence and metastasis, and current treatment options remain limited. There is strong evidence for the involvement of Notch signaling in TNBC. Notch1 is highly expressed in Basal-like 1 (BL1) and especially Mesenchymal-Stem-Like (MSL) TNBCs. Expression of Notch1 protein correlates with pAKT and nuclear NF-κB in TNBC specimens. Expression of Notch1 and its ligand Jagged1 correlate with poor prognosis. NF-κB also plays key roles in promoting cancer cell survival in TNBC. Notch-NF-κB cross-talk through several mechanisms has been demonstrated in T-cell acute leukemia, cervical cancer and Luminal A breast cancer cells, but not TNBC. Here, we demonstrate that Notch1 promotes cell survival in MDA-MB-231 cells, representative of MSL TNBC, in part by activating NF-κB. Notch activation by Jagged1-expressing stromal cells enhances transcription of the anti-apoptotic gene cIAP-2 (BIRC3), a known NF-κB target. This event is dependent on recruitment to the cIAP-2 promoter of NF-κB subunits, IKKα and Notch1. However, Notch1 is recruited to the chromatin later than NF-κB subunits and IKKα, suggesting that early, non-nuclear events contribute to this process. NF-κB activation correlates with AKT activation as revealed by S473 phosphorylation. Pharmacological inhibition of AKT or expression of dominant-negative AKT decreases NF-κB activity. Inhibition of Notch activity through GSIs (γ-secretase inhibitors) leads to decreased AKT phosphorylation. Our results indicate that AKT activation is independent of canonical nuclear Notch1 partner CBF-1. Short term exposure of MDA-MB-231 cells (MSL, PTEN wild-type), but not MDA-MB-468 cells (BL1, PTEN-null) to recombinant Jagged1 leads to AKT phosphorylation within 1 hour. This is suppressed by dual mTORC1/2 inhibitors, PI3K inhibitors and IKKα inhibitors but not Everolimus (mTORC1-selective inhibitor). Pharmacological inhibition of AKT, or mTORC1/2 or IKKα decreases AKT phosphorylation and cell proliferation. These observations support a model where canonical and non-canonical mechanisms downstream of Notch1 trigger AKT phosphorylation and NF-κB activation in PTEN wild type TNBC cells. Rapid AKT phosphorylation downstream of Notch1 requires mTORC2, PI3K and IKKα, and contributes to NF-κB activation. Notch1 has been shown to activate mTORC2 in T-cells, while IKKα has been reported to activate mTORC2 in other models. Our data indicate that this pathway may be active in some TNBC subtypes as well. Our data indicate that therapeutic regimens targeting this pathway deserve further investigation in PTEN-wild type but not PTEN-mutant TNBCs.

Citation Format: Fokhrul Hossain, Yin Peng, Antonio Pannuti, Kandis Backus, Todd Eliot Golde, Barbara Osborne, Lucio Miele. A novel non-canonical Notch-AKT- NF-κB pathways in triple negative breast cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4616.

Inhibition of Fatty Acid Oxidation Modulates Immunosuppressive Functions of Myeloid-Derived Suppressor Cells and Enhances Cancer Therapies

Myeloid-derived suppressor cells (MDSC) promote tumor growth by inhibiting T-cell immunity and promoting malignant cell proliferation and migration. The therapeutic potential of blocking MDSC in tumors has been limited by their heterogeneity, plasticity, and resistance to various chemotherapy agents. Recent studies have highlighted the role of energy metabolic pathways in the differentiation and function of immune cells; however, the metabolic characteristics regulating MDSC remain unclear. We aimed to determine the energy metabolic pathway(s) used by MDSC, establish its impact on their immunosuppressive function, and test whether its inhibition blocks MDSC and enhances antitumor therapies. Using several murine tumor models, we found that tumor-infiltrating MDSC (T-MDSC) increased fatty acid uptake and activated fatty acid oxidation (FAO). This was accompanied by an increased mitochondrial mass, upregulation of key FAO enzymes, and increased oxygen consumption rate. Pharmacologic inhibition of FAO blocked immune inhibitory pathways and functions in T-MDSC and decreased their production of inhibitory cytokines. FAO inhibition alone significantly delayed tumor growth in a T-cell-dependent manner and enhanced the antitumor effect of adoptive T-cell therapy. Furthermore, FAO inhibition combined with low-dose chemotherapy completely inhibited T-MDSC immunosuppressive effects and induced a significant antitumor effect. Interestingly, a similar increase in fatty acid uptake and expression of FAO-related enzymes was found in human MDSC in peripheral blood and tumors. These results support the possibility of testing FAO inhibition as a novel approach to block MDSC and enhance various cancer therapies.

Inhibition of fatty acid oxidation blocks asthma in mice (HYP2P.340)

Background: There has been a growing appreciation for the role of energy metabolic pathways in the differentiation and function of immune cells. Unpublished findings from our laboratory suggest that inhibiting fatty acid oxidation (FAO) modulates the activation and function of tumor-infiltrating myeloid cells, indicating a potentially important role for FAO in inflammation and thus inflammatory diseases such as asthma. Objective: We sought to test the hypothesis that FAO plays an important role in asthma manifestation. Methods: Etomoxir, an inhibitor of the FAO rate-limiting enzyme carnithine palmitoyltransferase-1, was used to test our hypothesis in an ovalbumin-based murine model of asthma. Results: Etomoxir treatment thirty minutes after ovalbumin challenge resulted in a significant reduction in the recruitment of eosinophils and macrophages into the lungs without a prominent effect on the total number of lymphocytes. Etomoxir treatment also prevented ovalbumin-induced hyperresponsiveness. The protective effects of etomoxir were associated with a decrease in Th2 cytokines and ovalbumin-specific IgE production. Additionally, the frequency of splenic macrophages was lower in etomoxir-treated mice, compared with control. Conclusions: Our preliminary data suggest the inhibition of FAO as a likely strategy to block asthma traits. As such, we are currently uncovering the mechanisms by which FAO inhibition reduces the pathogenesis of asthma.

Inhibiting fatty acid oxidation blocks the immunosuppressive functions of myeloid-derived suppressor cells and enhances cancer therapies (TUM6P.960)

Myeloid-derived suppressor cells (MDSC) promote tumor growth by inhibiting T cell immunity through various mechanisms including the depletion of arginine and the production of nitric oxide and peroxinitrites. Blocking of any single mechanism has only moderate therapeutic effects because MDSC show high adaptability and upregulate the remaining suppressive pathways. We studied whether disrupting the energy metabolic pathway(s) of MDSC would modulate their immunosuppressive functions and enhance antitumor effects. Using several murine tumor models, we found that tumor-infiltrating MDSC (T-MDSC) increased fatty acid uptake and activated fatty acid oxidation (FAO). This was accompanied by increased mitochondrial mass and function, key FAO enzymes, and oxygen consumption rate. These metabolic changes paralleled with the induction of immunosuppressive mechanisms. Inhibition of FAO blocked immunosuppressive mechanisms and functions in T-MDSC and decreased their production of immunosuppressive cytokines. Interestingly, it also diminished the number of regulatory T cells and resulted in a T cell-dependent decrease in tumor growth. FAO inhibition also significantly increased antitumor effects with low-dose chemotherapy or cellular immunotherapy. Human MDSC demonstrated similar characteristics. These data support the possibility of testing FAO inhibition as a novel approach to block MDSC and enhance various cancer therapies. *F. Hossain and A.A. Al-Khami contributed equally to this work.

Measuring function after hip and knee surgery: the evidence to support performance-based functional outcome tasks

Accurate, reproducible outcome measures are essential for the evaluation of any orthopaedic procedure, in both clinical practice and research. Commonly used patient-reported outcome measures (PROMs) have drawbacks such as 'floor' and 'ceiling' effects, limitations of worldwide adaptability and an inability to distinguish pain from function. They are also unable to measure the true outcome of an intervention rather than a patient's perception of that outcome. Performance-based functional outcome tools may address these problems. It is important that both clinicians and researchers are aware of these measures when dealing with high-demand patients, using a new intervention or implant, or testing a new rehabilitation protocol. This article provides an overview of some of the clinically-validated performance-based functional outcome tools used in the assessment of patients undergoing hip and knee surgery.

Turner’s Syndrome in Adulthood and Cytogenetics

Aims: Turner’s syndrome is a chronic disease of chromosomal aberration. The purpose of the study was to find out the accurate identification of cell line, which is critical for cytogenetic studies, genetic counseling, phenotypic studies carried out with few reconstructive procedures to plan future sexual and reproductive life. Methods: This study design was a prospective hospital based clinical study. In this study, ninety six patients were studied with secondary sex characters with relevant ultrasonogram findings and hormonal assay who underwent karyotyping in Bangabandhu Sheikh Mujib Medical University, Dhaka for a study period of ten years from October 1997 to October 2007. Results: Among 96 patients, 62.5 % of the patients were from 15-18 years. Four girls who were less than 15 years came with Turner’s and testicular stigmata. Twenty women aged more than 26 years presented with coital problems.  Around 72.9% had no secondary sexual character, 20.83% had normal female type of secondary sex character, and 6.25% had virilizing type of secondary sexual character. Karyotyping of the cases revealed 72.9% (n = 70) had 45XO pattern, which belong to the Turner's stigmata and correlated well with the hormone profile. Whereas, 20.83% (n = 20) had 46XX pattern and 6.25% (n = 6) had 46XY pattern with testicular feminization syndrome with inguinal testis. Conclusions: About 60% of cases were in the 15-18 years age group. Most of the patients presented with no secondary sexual characteristics. 45XO chromosomal pattern was the most common presenting in 72.9% cases. DOI: http://dx.doi.org/10.3126/njog.v9i2.11744 

Cigarette Smoke Alters the Hematopoietic Stem Cell Niche

Effects of tobacco smoke on hematologic derangements have received little attention. This study employed a mouse model of cigarette smoke exposure to explore the effects on bone marrow niche function. While lung cancer is the most widely studied consequence of tobacco smoke exposure, other malignancies, including leukemia, are associated with tobacco smoke exposure. Animals received cigarette smoke exposure for 6 h/day, 5 days/week for 9 months. Results reveal that the hematopoietic stem and progenitor cell (HSPC) pool size is reduced by cigarette smoke exposure. We next examined the effect of cigarette smoke exposure on one supporting cell type of the niche, the mesenchymal stromal cells (MSCs). Smoke exposure decreased the number of MSCs. Transplantation of naïve HSPCs into irradiated mice with cigarette smoke exposure yielded fewer numbers of engrafted HSPCs. This result suggests that smoke-exposed mice possess dysfunctional niches, resulting in abnormal hematopoiesis. Co-culture experiments using MSCs isolated from control or cigarette smoke-exposed mice with naïve HSPCs in vitro showed that MSCs from cigarette smoke-exposed mice generated marked expansion of naïve HSPCs. These data show that cigarette smoke exposure decreases in vivo MSC and HSC number and also increases pro-proliferative gene expression by cigarette smoke-exposed MSCs, which may stimulate HSPC expansion. These results of this investigation are clinically relevant to both bone marrow donors with a history of smoking and bone marrow transplant (BMT) recipients with a history of smoking.