bluuebunny/crossref_metadata_2025 huggingface dataset:
7277 Diabetic Ketoacidosis As The First Manifestation Of Ectopic Cushing’s Syndrome
Authors: Saudade Medeiros Regina , Pereira Bernardo , Pataco Andreia , Senra Catarina , João Ponte Maria , Anselmo João , Sousa Isabel
Published: October 2024

Disclosure: R.S. Medeiros: None.

Introduction: Ectopic Cushing’s Syndrome (ECS) represents 10-20% of all ACTH-dependent CS, and the majority of cases arise from lung carcinoids. These indolent lesions usually evolve clinically over 6-24 months, whereas carcinomas are associated with faster onset of ECS. Diabetic Ketoacidosis (DKA) as a presenting manifestation of Cushing’s Syndrome (CS) is very rare, with the few cases published to date related to Cushing’s disease. Clinical Case: A 42-year-old woman was admitted in the emergency room with DKA and COVID-19. During stabilization, florid CS was clinically suspected. She reported a 6-month history of secondary amenorrhea, lack of concentration and memory, easy bruising, proximal myopathy with frequent falls evolving to daily life dependency from relatives. She also reported a 2-month diagnosis of dyslipidemia, Diabetes and hypertension, and a diagnosis of atypical pneumonia 6 months ago. Physical exam showed typical cushingoid appearance, especially for marked limb sarcopenia and proximal myopathy. An overnight dexamethasone suppression test (morning cortisol: 25.7 ug/dL), 24h urinary free cortisol (UFC; 1072.5 ug/dL; reference: <176) and serum cortisol at 23h00 (25.5 ug/dL) confirmed CS. ACTH-dependent CS was diagnosed. She had non-suppressible serum cortisol in high dose dexamethasone suppression test, and CRH stimulation test was suggestive of Cushing’s disease only by a 20% rise of cortisol at 30 minutes. Pituitary MRI was normal. Inferior Petrosal Sinus sampling was postponed for several months due to healthcare strikes. The patient started 750 mg of metyrapone in three divided doses but rapidly decreased the dose and stopped it due to clinical resolution of CS, a dramatic improvement of all glucocorticoid-related comorbidities leading to discontinuation of statin, insulin, main oral anti-hyperglycemic and antihypertensive medications, and normal midnight salivary cortisol and 24h UFC. She remained in this eucortisolemic state for 12 months. Thoracic CT scan revealed thymic hyperplasia and a 25x15 mm well-defined nodule in the lingula. A 68Ga-DOTANOC PET/CT showed a single uptake in the same lung region. The patient underwent lingulectomy plus excisional biopsy of interlobar lymph nodes, and pathology revealed a low-grade neuroendocrine tumor (Ki67<2%, <2 mitosis) without involved lymph nodes. The patient is weaning off from physiologic doses of hydrocortisone. Conclusion: DKA can rarely be the presenting manifestation of severe CS, including ECS. Clinicians should suspect on this etiology of DKA based on clinical signs and cumulative morbidity not typical of a young patient. This hint would lead to the expedite implementation of targeted therapies for initial stabilization of the CS patient, and the timely institution of a proper diagnostic approach and definitive treatment of this challenging patients.

Presentation: 6/2/2024
7232 Direct m6A mRNA-Seq In Endocrine- Resistant And Sensitive Breast Cancer Cells
Authors: Petri B J , Valdes B L , Piell K M , Rouchka E C , Klinge C M
Published: October 2024

Disclosure: B.J. Petri: None. B.L. Valdes: None. K.M. Piell: None. E.C. Rouchka: None. C.M. Klinge: None.

Acquired resistance to endocrine therapies (ET) in patients with estrogen receptor α (ER+) breast tumors results in metastatic spread. RNA modifications including N6-methyladenosine (m6A) play crucial roles in the post-transcriptional regulation of gene expression and have been implicated in cancer progression. We hypothesized that m6A epitranscriptomic alterations are associated with pathways in ET resistance. Direct-RNA sequencing technology (nanopore) was used to detect and map m6A modifications at single-nucleotide resolution to comprehensively profile m6A modifications in ET-resistant LCC9 and ET -sensitive MCF-7 breast cancer cell lines with or without 4-hydroxytamoxifen (4-OHT) treatment. Additionally, MCF-7 cells were treated with the METTL3 inhibitor STM2457 to identify m6A positions and transcripts directly regulated by METTL3 activity. We developed a new statistical method by integrating m6Anet, an existing machine-learning algorithm designed to call m6A modified bases, with a generalized linear model following a binomial distribution analysis to identify significant differential m6A modification ratios (DMR). We identified 61 transcripts with DMR between vehicle-treated LCC9 compared to MCF-7 cells and 323 transcripts with DMRs between 4-OHT-treated LCC9 and MCF-7 cells. Fewer transcripts showed DMR after 4-OHT treatment in MCF-7 (41) versus LCC9 cells (399). Thus, more changes in m6A DMRs were detected in response to 4-OHT in the ET-resistant LCC9 versus ET-sensitive MCF-7 cells with “translation elongation” as the top pathway in enrichment analysis. STM2457 treatment resulted in significant changes to DMRs in MCF-7 cells with or without 4-OHT treatment and altered gene expression patterns associated with “cytosolic ribosome” in enrichment analysis. We identified many genes with multiple m6A modifications, e.g., AMIGO2 with 14 m6A sites at METTL 3 target DRACH motifs in MCF-7 cells, compared to no m6A modification in AMIGO2 in LCC9 cells. Our findings reveal distinct m6A modification patterns in ET-resistant LCC9 breast cancer cells compared to their ET-sensitive parental MCF-7 cells and in response to 4-OHT, suggesting a potential role for epitranscriptomic alterations in the development of ET resistance.

Presentation: 6/3/2024
8767 Ectopic Cushing's Disease
Authors: Kothari V A , Yavuz S
Published: October 2024

Disclosure: V.A. Kothari: None.

Here we present the diagnostic journey of a patient with Cushing's syndrome attributed to a rare and elusive culprit—a neuroendocrine tumor that aberrantly produces adrenocorticotropic hormone (ACTH). An 83-year-old female with PMH of Graves' disease well-controlled on methimazole 5 mg daily presented w/ AMS & worsening weakness and was found to have severe hypokalemia w/ K of 2.2. A CT chest done a month prior for bronchitis showed a right lower lobe lung nodule and a prior CT Abd also done a month prior showed an incidental pancreatic cyst of 1.5 cm and bilateral adrenal thickening. In addition, the patient had progressively worsening diabetes and proximal muscle loss. Patient was started on K supplementation and also spironolactone. A renin and aldosterone level were obtained which were 0.47 and <1, respectively which ruled out hyperaldosteronism. Her insulin requirements had significantly escalated. Given the patient's skin changes with petechiae along with the findings above, the patient underwent a low-dose DST twice which showed elevated AM cortisol of 76.4 & 69.6 respectively. Dexamethasone level was appropriately elevated at 217. ACTH was 149. A 24 hr urine cortisol was repeated twice and showed 4477.6 and 7107.2 respectively. MRI brain showed a flatten pituitary and empty sella. Amiloride and ketoconazole were started. Spironolactone was increased to 200 mg. Ga-68 DOTATE PET/CT was done however did not show a distinct source lesion. A few weeks later,the patient again had to go to ER due to profound hyperkalemia and hyponatremia. Her medications were adjusted. While hospitalized, she underwent biopsy and cryoablation of the right lung nodule w/ subsequent immediate reduction in ACTH levels. However, although the ACTH level initially declined and a subsequent CT chest also showed the ablation zone to encompass the whole tumor, the patient again had worsening of ACTH & cortisol causing hypokalemia again. It was unclear if the patient's active Cushing's disease was due to residual tumor or other areas of carcinoid as the lung nodule was dotatate and FDG negative. Given the active Cushing's disease, ketoconazole 200 mg BID was restarted. Her condition continued to worsen despite escalating doses of ketoconazole. Due to proximal myopathy, she was unable to ambulate on her own requiring significant assistance. Definitive treatment was discussed with the patient and her family given the progressive functional decline. Broached adrenal ablation versus adrenalectomy was discussed and bilateral adrenalectomy was eventually decided upon and scheduled. This case highlights the rare occurrence of ectopic ACTH producing neuroendocrine tumors causing Cushing's syndrome. It underscores the need for advanced diagnostic approaches and collaborative healthcare efforts in managing uncommon endocrine disorders.

Presentation: 6/2/2024
7908 GPNMB Promotes Tumor Growth And Is A Biomarker For Lymphangioleiomyomatosis (LAM)
Authors: Gibbons Erin , Taya Manisha , Wu Huixing , Lopa Samia , Moss Joel , Henske Elizabeth P , McCormack Francis X , Hammes Stephen R
Published: October 2024

Disclosure: E. Gibbons: None. M. Taya: None. H. Wu: None. S. Lopa: None. J. Moss: None. E.P. Henske: None. F.X. McCormack: None. S.R. Hammes: None.

Lymphangioleiomyomatosis (LAM) is a rare, progressive cystic lung disease affecting almost exclusively female-sexed individuals. The cysts represent regions of lung destruction caused by smooth muscle tumors containing mutations in one of the two tuberous sclerosis (TSC) genes. mTORC1 inhibition slows but does not stop LAM advancement. Furthermore, monitoring disease progression is hindered by insufficient biomarkers. Therefore, new treatment options and biomarkers are needed. LAM cells express melanocytic markers, including Glycoprotein Non-Metastatic Melanoma Protein B (GPNMB). The function of GPNMB in LAM is currently unknown; however, GPNMB’s unique cell surface expression on tumor versus benign cells makes GPNMB a potential therapeutic target, and persistent release of its extracellular ectodomain suggests potential as a serum biomarker. Here we establish that GPNMB regulates TSC2-null tumor cell invasion as well as TSC2-null xenograft tumor growth, and that GPNMB expression is dependent on mTORC1 signaling. Further, we show that GPNMB’s ectodomain is released from the cell surface of TSC2-null cells by ADAM10 and 17 proteases, and we identify the protease target sequence on GPNMB. In fact, mutating this cleavage sequence so that the GPNMB ectodomain can no longer be shed results in cessation of TSC2-null tumor growth. Finally, we demonstrate that GPNMB’s ectodomain is present at higher levels in LAM patient serum compared to healthy controls, and that ectodomain levels decrease with mTORC1 inhibition, making it a potential LAM biomarker.

Presentation: 6/3/2024
8770 Highly Multiplexed Mapping Of The Ductal Carcinoma In Situ Ecosystem To Predict Disease Outcome
Authors: Wilson G M , Doan T B , Guild B J , Pathmanathan N , Graham J D
Published: October 2024

Disclosure: G.M. Wilson: None. T.B. Doan: None. B.J. Guild: None. N. Pathmanathan: None. J.D. Graham: None.

Mammographic screening programs have resulted in remarkable improvements in breast cancer survival due to early-stage detection. However, this has resulted in a dramatic increase in the detection of non-invasive ductal carcinoma in situ (DCIS), a non-obligate precursor of invasive ductal carcinoma (IDC), which is confined to the ducts and surrounded by a normal myoepithelial cell layer. Many DCIS cases will not progress to IDC within the lifetime of the patient. However, there are limited tools to accurately predict progression, thus virtually all DCIS is surgically removed, and most patients receive adjuvant radiotherapy as it halves recurrence rates. This likely represents overtreatment for a majority of patients. Emerging evidence has revealed that the adjacent microenvironment becomes progressively altered in DCIS and IDC compared to normal tissue, and this is correlated with disease outcome. The objective of this study was to investigate changes to the DCIS microenvironment during disease progression and identify disease states that predict patient outcome. We used immunohistochemistry and imaging mass cytometry with a well-annotated cohort of DCIS, with or without adjacent IDC, to measure a panel of 40 phenotypic and functional markers that allowed us to distinguish the diverse cell populations present in the tissues. We observed striking changes to almost all cell types within the DCIS tissue when comparing pure DCIS cases to DCIS adjacent to IDC. In particular, there were considerable changes to tissue-resident immune populations, with differences observed in the type, location and population size of a variety of immune cell subsets, in IDC-associated DCIS compared with DCIS-only cases. Computational mapping of cell type communities in pure and IDC-adjacent DCIS tissues revealed specific differences that could be used to predict the emergence of invasive disease, informing clinical management of this good prognosis malignancy and potentially avoiding over-treatment.

Presentation: 6/3/2024
8817 IGF-II Regulates Magmas A Mitochondrial Protein Required For Cell Viability And ROS Protection
Authors: Granados Katherine , Durán Alfonso , Almaguel Frankis , De Leon Daisy
Published: October 2024

Disclosure: K. Granados: None. A. Durán: None. F. Almaguel: None. D. De Leon: None.

Our laboratory previously showed that Insulin-like growth factor II (IGF-II) promotes cell proliferation, inhibits apoptosis and induces chemoresistance of Breast Cancer (BC) cells. We demonstrated that IGF-II achieves this by inhibiting pro-apoptotic proteins and stimulating anti-apoptotic proteins. Those studies also demonstrated that IGF-II prevented mitochondrial induced apoptosis by inhibiting depolarization of the mitochondrial membrane. Thus, IGF-II regulates the mitochondria to prevent cell death and to promote tumor growth and chemoresistance. Since IGF-II regulates mitochondrial proteins, we decided to assess how IGF-II regulates MAGMAS, a protein located in the inner mitochondrial membrane that is a critical component of a complex that controls mitochondrial protein import and ROS. Of note, MAGMAS was recently identified as being highly expressed in breast cancer, prostate cancer and during early fetal development which parallels IGF-II expression. Immunostaining of TNBC showed high levels of IGF-II and MAGMAS. Thus, our hypothesis is that IGF-II regulates MAGMAS and IGF-II secreting breast cancer cells will express higher levels of MAGMAS. Our preliminary results of rtPCR and Western blotting experiments validated our hypothesis demonstrating that IGF-II regulated the transcription of MAGMAS. To characterize the mechanisms by which IGF-II regulates MAGMAS, we chose the triple negative breast cancer (TNBC) cell line CRL-2335 which we demonstrated produces high levels of IGF-II and MAGMAS. CRL2335 cells were established from an AA TNBC patient and they express high levels of IGF-II and MAGMAS. Confocal microscopy and Western blotting and cellular fractionation were used to assess IGF-II regulation of MAGMAS in TNBC cells. The expression of MAGMAS was analyzed in wild CRL-2335, and IGF-II antisense transfected CRL-2335 cells and compared to cells treated with IGF-II. Results showed that CRL-2335 express high levels of MAGMAS in the mitochondria and blocking the expression of IGF-II by antisense technology significantly decreased MAGMAS. Exogenous IGF-II treatment to the antisense cells increased MAGMAS as demonstrated by Immunofluorescence and WB. Since IGF-II increases the localization of MAGMAS to the mitochondria we propose that IGF-II regulates MAGMAS to protect cancer cells from ROS induced cell death and chemoresistance. Completion of this study will validate IGF-II as a regulator of MAGMAS. Validation of IGF-II regulation of MAGMAS represents an important new tool for the treatment of TNBC.

Presentation: 6/2/2024
6603 Impact Of The Monocarbonyl Analogs Of Curcumin, C66 And B2BrBC, On The Protein Expression Of Epithelial And Mesenchymal Markers In MCF-7 Breast Cancer Cells
Authors: Stojchevski Radoslav , Lavi Aaron , Bogdanov Jane , Hadzi-Petrushev Nikola , Mladenov Mitko , Poretsky Leonid , Bogdanov Avtanski Dimiter
Published: October 2024

Disclosure: R. Stojchevski: None. A. Lavi: None. J. Bogdanov: None. N. Hadzi-Petrushev: None. M. Mladenov: None. L. Poretsky: None. D.B. Avtanski: None.

The synthesis of monocarbonyl analogs of curcumin (MACs) presents a solution to the challenges posed by curcumin, a natural polyphenol extracted from the roots of the turmeric plant (Curcuma longa), which is known for its antioxidant and anti-inflammatory properties. The limitations of curcumin, including poor stability, low bioavailability, and rapid metabolism, hinder its application, and MACs, designed without a β-diketone moiety, address these drawbacks and exhibit enhanced stability and bioavailability. This study aimed to assess the effects of two monocarbonyl analogs of curcumin, (2E,6E)-2,6-bis[(2-trifluoromethyl)benzylidene]cyclohexanone (C66) and (2E,6E)-2,6-bis(2-bromobenzylidene)cyclohexanone (B2BrBC), on epithelial-to-mesenchymal transition (EMT) in MCF-7 breast cancer cells using western blot analysis. Our previous findings indicated that these analogs can potentially affect EMT by modulating the epithelial and mesenchymal gene expression. MCF-7 cells were cultured in complete medium supplemented with EMT-inducing factors for two days, followed by C66 and B2BrBC administration (100 µM) for three additional days. After the experiments, proteins were extracted, and western blot analyses were performed to measure the expression levels of various epithelial and mesenchymal markers (E-cadherin, N-cadherin, SNAI1, and Claudin-1). The results revealed that both C66 and B2BrBC increased the protein levels of the epithelial marker E-cadherin and suppressed those of the mesenchymal marker N-cadherin. Moreover, C66 and B2BrBC decreased the protein expression of the transcription factor SNAI1 and transmembrane protein Claudin-1. Between the two MACs, B2BrBC showed a more pronounced effect on N-cadherin expression, while C66 was more potent in suppressing SNAI1 protein expression. Our findings demonstrate that C66 and B2BrBC counteract EMT, contributing to the potential therapeutic applications of MACs in managing breast cancer progression.

Presentation: 6/3/2024
7076 Inhibiting Oxidosqualene Cyclase, An Enzyme In The Cholesterol Biosynthetic Pathway, Suppresses Lung Metastasis Of Triple-Negative Breast Cancer Cells
Authors: Liang Yayun , Hyder Salman M
Published: October 2024

Disclosure: Y. Liang: None. S.M. Hyder: None.

Triple-negative breast cancers (TNBC) lack ER, PR and Her2neu proteins that are commonly targeted in breast cancer therapies. As a consequence, women who suffer from TNBC have poor prognosis and limited treatment options, and are usually administered toxic, non-specific chemotherapeutic agents. Drug-resistance almost always occurs, leading to tumor metastasis, the main cause of patient death. New non-toxic therapeutic strategies to control metastasis of TNBC are urgently needed. Cholesterol is an essential structural and functional component of cell membranes that is necessary for the growth of both primary tumors and metastatic colonies that reside in distant organs. Therefore, inhibiting cholesterol production is an attractive therapeutic strategy. Treatment with statins, a class of cholesterol biosynthesis inhibitors that target HMGCoA-reductase, is associated with certain undesirable side effects; consequently, we targeted oxidosqualene cyclase (OSC), an enzyme that occurs downstream of HMGCoA-reductase in the cholesterol biosynthetic pathway, to disrupt tumor metastasis. Potent small molecule inhibitors of OSC have been identified. RO 48-8071 (4′-[6-(allylmethylamino)hexyloxy]-4-bromo-2′-fluorobenzophenone fumarate) (RO), has emerged as a useful chemotherapeutic agent for treating several forms of primary tumors. We developed a mouse model for studying lung metastasis using a MDA-MB-231 variant (LM2) TNBC cell line obtained from Dr. Massagué (Memorial Sloan-Kettering Cancer Center). These are aggressive cells, and injection of only 2 X 105 cells produces detectable lung metastatic colonies in approximately 4-6 weeks. We inoculated female nu/nu mice, 5-6 weeks old, with 2 X 105 MDA-MB-231/LM2 cells in 0.1 ml DMEM/F12 medium without serum via tail vein. Five days after tumor cell inoculation animals received 20 mg/kg (n=6), 40 mg/kg (n=7) RO (ip) or vehicle alone (n=7) every other day for two weeks. Animals were then sacrificed, and both lungs harvested and immediately fixed in Bouin’s fixative. Metastatic colonies on the lung surface were identified and counted under a dissecting microscope. Our study showed that RO effectively reduced lung metastasis without affecting animal weight. Compared with 56 + 7 colonies (Mean ± SEM) in controls given vehicle alone, RO significantly reduced lung metastatic colonies to 28 ± 5 in animals exposed to 20 mg/kg and 6 ± 1 in 40 mg/kg treated animals (p<0.05, ANOVA). Reduction in number of colonies in 40 mg/kg group was also significantly different from colonies counted in 20 mg/kg treated animals. Our study is the first to demonstrate that disruption of cholesterol biosynthesis in a model of human TNBC leads to reduced metastasis in lungs. Further studies will determine mechanisms through which RO suppresses TNBC metastasis to the lungs. Supported by Zalk Missouri Professor Endowment Funds.

Presentation: 6/3/2024
9260 Insulin Receptor Signaling And Racial Disparities In Triple Negative Breast Cancer
Authors: Joy Engel Alexis , Samuel Krupa , Bass Ilana R , Lin Sylvia , Markella Antoniou Irini , Yagnik Radhi , LeRoith Derek , Bickell Nina A , Jane Gallagher Emily
Published: October 2024

Disclosure: A.J. Engel: None. K. Samuel: None. I.R. Bass: None. S. Lin: None. I. Antoniou: None. R. Yagnik: None. D. LeRoith: None. N.A. Bickell: None. E.J. Gallagher: Consulting Fee; Self; Novartis Pharmaceuticals.

Introduction: Obesity and type 2 diabetes are associated with poor breast cancer (BC) prognosis. These disorders, along with hyperinsulinemia are more common in Black than in White women. Black women also have higher rates of triple negative breast cancer (TNBC), and greater breast cancer mortality than White women. We hypothesized that Black women with TNBC have worse outcomes in part due to tumor promoting effects of hyperinsulinemia via the insulin receptor (IR) signaling pathway. Methods: From our IRB-approved, multi-institutional, cross-sectional, NIH-funded, study of women with newly diagnosed BC, we identified women with TNBC. We performed immunohistochemistry (IHC) analysis of formalin-fixed-paraffin-embedded tumor samples from 45 self-identified Black women and 48 self-identified White women. We quantified the BC expression of IR (n=92), IGF1R (n=92), pERK (n=91), FOXO3a (n=90) for intensity (none=0, weak=1, moderate=2, intense=3). In subsequent analysis, 0 and 1 intensity IHC staining were considered negative, and 2 and 3 were considered positive. Quantification was performed with reviewers blinded to clinical information. Clinical information (age, race, body mass index [BMI], waist circumference, fasting insulin, BC Nottingham Prognostic Index [NPI]) was evaluated after IHC scoring. Statistical proportions were compared using Fishers Exact test, and continuous variables were evaluated using parametric or non-parametric tests, as appropriate. Results: Positive IR staining was seen in 64% of samples (n=59), 74% (n=68) for IGF1R, 68% (n=62) for FOXO3a and 43.3% (n=39) for pERK. Positive IR staining was more prevalent in Black women than White women (P=0.003) but was not significantly associated with age or NPI. IGF1R, FOXO3a, pERK positive staining were not associated with race or NPI. Positive IR staining was also associated with higher BMI, waist circumference, and fasting insulin (P<0.05 for all). Positive IGF1R, FOXO3a, pERK staining were not associated with any of these factors. Conclusions: We found that 64% of TNBCs had positive expression of IR, and IR expression was more prevalent in tumors from Black women and associated with higher insulin levels, suggesting that tumors from Black women may be more sensitive to the tumor promoting effects of systemic hyperinsulinemia.

Presentation: 6/2/2024
7948 Integration Of Epigenomics And Metabolomics Reveals New Signaling In Aggressive Thyroid Cancer
Authors: Sanghi A , Wu S , Chou T , Orloff L A , Kasowski M , Snyder M
Published: October 2024

Disclosure: A. Sanghi: None. S. Wu: None. T. Chou: None. L.A. Orloff: None. M. Kasowski: None. M. Snyder: None.

Although genetic mutations are causal in human cancers, the contribution of chromatin changes to cancer onset and progression remains less well understood. Multi-omics profiling of human tumors can provide insight into how alterations in chromatin structure are propagated through the pathway of gene expression to result in cancer signaling. We applied multi-omics profiling of 36 human thyroid cancer primary tumors, metastases, and patient-matched normal tissue. Over 80% of the tumors harbored BRAFV600E mutations, and the remaining tumors mostly had activating mutations in the MAPK pathway. Through quantification of chromatin accessibility associated with active transcription units and global protein expression, we identify local enhancers that are highly correlated with coordinated RNA and protein expression. The enhancers are predicted to be actively bound by MAPK transcription factor, indicating they are under MAPK control. These cancer-specific enhancers associated with upregulation of lysosomal peptidase expression and dipeptide abundance in tumors. We show that upregulated dipeptides stimulate MAPK activity, and BRAF inhibition results in loss of lysosomal function in mutants. Perturbation of lysosomal peptidases and dipeptide abundance decreases MAPK activity only in mutant cells compared to wildtype. These analyses suggest that BRAF thyroid tumors integrate MAPK-driven epigenetic regulation with lysosomal metabolite signaling in a positive feedback circuit. Using local cancer-specific epigenetic features, we isolated key cancer signaling, making way for potential targets for cancer therapeutics.

Presentation: 6/3/2024
9304 Integration Of Glucocorticoid And Mineralocorticoid Receptor Signaling In Triple-Negative Breast Cancer Models
Authors: Harshita Posani Sai , Lange Carol A
Published: October 2024

Disclosure: S. Posani: None. C.A. Lange: None.

Glucocorticoid receptors (GR) sense a convergence of host and cellular stress signaling to orchestrate an array of advanced cancer phenotypes associated with triple-negative breast cancer (TNBC) progression. The Lange lab reported p38 MAP kinase mediated phosphorylation of GR at serine 134 (Ser134) in response to tumor microenvironment-derived cytokines, such as TGF-beta-1. Phospho-Ser134-GR (p-Ser134-GR) upregulated gene sets that promote cancer cell survival, chemoresistance, altered metabolism, and migratory/invasive behavior in TNBC models. In addition to acting as ligands for GR, glucocorticoids also bind to and activate another closely related steroid hormone receptor - the mineralocorticoid receptor (MR). The elucidation of functional responses upon activation of MR remains an untapped area in breast cancer research. Our probe into public datasets (METABRIC, and TCGA) demonstrated significantly higher expression of MR transcripts in TNBC relative to luminal breast cancer. High expression of MR predicted worse overall survival in ERα-negative breast cancer patients compared to the low expressing cohort. Silencing of MR was carried out by siRNA-mediated knockdown and treatment with spironolactone, a competitive MR antagonist. Interestingly, MR knockdown significantly reduced the TGF-beta-1 induced migratory capacity of breast cancer cells compared to the wild-type control cells expressing endogenous MR. This biological phenotype of decreased TGF-beta-1 induced migration upon MR knockdown parallels the reduced migration we observed when the p38 MAPK site (Ser134 on GR was mutated to Ala in TNBC models. We therefore hypothesized that MR and GR may cooperate under the influence stress signaling in response to growth factors and cytokines abundantly present in the tumor-microenvironment. Preliminary data suggest that cytoplasmic p-Ser134-GR/MR complexes associate upon TGF-beta-1 treatment, while GR and/or MR ligands stimulate the formation of nuclear GR/MR complexes. We are further investigating cytokine- and stress-signal mediated regulation of GR/MR complexes and their functional role in TNBC biology. The overarching goal of this study is to elucidate if MR is a required GR binding-partner and a potential therapeutic target in GR- and cytokine-driven metastatic TNBC processes.

Presentation: 6/2/2024
7873 Integration Of Glucocorticoid And Mineralocorticoid Receptor Signaling In Triple-Negative Breast Cancer Models
Authors: Posani S , Lange C A
Published: October 2024

Disclosure: S. Posani: None. C.A. Lange: None.

Glucocorticoid receptors (GR) sense a convergence of host and cellular stress signaling to orchestrate an array of advanced cancer phenotypes associated with triple-negative breast cancer (TNBC) progression. The Lange lab reported p38 MAP kinase mediated phosphorylation of GR at serine 134 (Ser134) in response to tumor microenvironment-derived cytokines, such as TGF-beta-1. Phospho-Ser134-GR (p-Ser134-GR) upregulated gene sets that promote cancer cell survival, chemoresistance, altered metabolism, and migratory/invasive behavior in TNBC models. In addition to acting as ligands for GR, glucocorticoids also bind to and activate another closely related steroid hormone receptor - the mineralocorticoid receptor (MR). The elucidation of functional responses upon activation of MR remains an untapped area in breast cancer research. Our probe into public datasets (METABRIC, and TCGA) demonstrated significantly higher expression of MR transcripts in TNBC relative to luminal breast cancer. High expression of MR predicted worse overall survival in ERα-negative breast cancer patients compared to the low expressing cohort. Silencing of MR was carried out by siRNA-mediated knockdown and treatment with spironolactone, a competitive MR antagonist. Interestingly, MR knockdown significantly reduced the TGF-beta-1 induced migratory capacity of breast cancer cells compared to the wild-type control cells expressing endogenous MR. This biological phenotype of decreased TGF-beta-1 induced migration upon MR knockdown parallels the reduced migration we observed when the p38 MAPK site (Ser134 on GR was mutated to Ala in TNBC models. We therefore hypothesized that MR and GR may cooperate under the influence stress signaling in response to growth factors and cytokines abundantly present in the tumor-microenvironment. Preliminary data suggest that cytoplasmic p-Ser134-GR/MR complexes associate upon TGF-beta-1 treatment, while GR and/or MR ligands stimulate the formation of nuclear GR/MR complexes. We are further investigating cytokine- and stress-signal mediated regulation of GR/MR complexes and their functional role in TNBC biology. The overarching goal of this study is to elucidate if MR is a required GR binding-partner and a potential therapeutic target in GR- and cytokine-driven metastatic TNBC processes.

Presentation: 6/2/2024
8437 Improved Quality Of Life&Blood Pressure Following Diagnosis And Medical Management Of Primary Aldosteronism (PA) / Georgian Experience
Authors: Gvazava Qetevan , Zavrashvili Nino , Shonia Natia
Published: October 2024

Disclosure: Q. Gvazava: None. N. Zavrashvili: None. N. Shonia: None.

Improved Quality of Life and Blood Pressure Following Diagnosis and Medical Management of Primary Aldosteronism (PA) - Georgian Experience Introduction: PA is the most common cause of secondary hypertension which still remains as an underdiagnosed condition in many countries, including Georgia. The choice of pharmacological or surgical therapy depends on the results of computed tomography scans of the adrenal glands and adrenal venous sampling. In patients with bilateral aldosterone hypersecretion, the optimal is a low-sodium diet and lifelong treatment with a mineralocorticoid receptor antagonist administered at a dosage to reach a high-normal serum potassium concentration. Discussion: 60 y/o male with a 17-year history of hypertension. He was treated with 3 drug-program: valsartan, amlodipine, bisoprolol. BP was not adequately managed with systolic BP >140 mm/Hg. Patient had a history of hypokalaemia and required regular potassium supplements. Patient had never been evaluated for possible PA. We planned case detection test, which came up positive, with increased aldosterone, suppressed renin concentration and increased aldosterone-renin ratio. Abdominal CT performed 1 year ago for another reason revealed “normal” adrenals.After discussing treatment options patient preferred medical management and Eplerenone was started, dose titrated accordingly, K supplements were discontinued which over time resulted in decrease in requirement of his other antihypertensive medications, with BP adequately managed. Patient’s quality of life improved significantly, he has shared his test results and progress on his follow up visits; He is very grateful and feels content with the treatment. We present another case of 49 y/o male patient with a 19 year history of hypertension. Patient was treated with 4 drug-regimen: Valsartan, Hydrochlorothiazide, Amlodipine, nebivolol with average BP findings – 140/90 mm/Hg.Case detection test was positive with increased aldosterone, suppressed renin and increased aldosterone-renin ratio. Patient required confirmatory testing. Salt loading was done which confirmed the diagnosis of PA. On unenhanced CT of the abdomen, bilateral adrenal hyperplasia was found. Patient was started on Eplerenone, on follow up, his BP findings are significantly improved, number of BP meds are also decreased. Conclusion: Diagnosis of PA provides clinicians with unique opportunity to cure or effectively improve hypertension and hypokalaemia, as well as to prevent potential target organ damage and complications. That’s why the importance of increased awareness and having high clinical suspicion cannot be understated.

Presentation: 6/3/2024
9316 Modulation Of Intracellular Lipid Access By ATGL Determines Ferroptosis Sensitivity In Castration-Resistant Prostate Cancer
Authors: Cao P , Awad D , Han J , Frigo D E
Published: October 2024

Disclosure: P. Cao: None. D. Awad: None. J. Han: None. D.E. Frigo: Grant Recipient; Self; GTx, Inc.. Other; Self; Familial relationship with Biocity Biopharmaceuticals, Hummingbird Bioscience, Bellicum Pharmaceuticals, Maia Biotechnology, Alms Therapeutics, Hinova Pharmaceuticals and Barricade Therapeutics.

Ferroptosis induction has recently been recognized as a novel therapeutic approach to alter the outcomes of drug-resistant cancer. Ferroptosis is cell death that is caused by the intracellular accumulation of toxic lipid hydroperoxides. Due to their elevated metabolism, castration-resistant prostate cancer (CRPCs) are highly prone to ferroptosis; yet, many of them manage to avert this cellular fate. We have identified a key enzyme involved in lipid metabolism, adipose triglyceride lipase (ATGL), that engenders CRPCs with the ability to resist ferroptosis. Our data has shown that ATGL deletion by CRISPR-Cas9 knockout method sensitized human CRPC cell lines such as C4-2, C4-2BLT, and PC3 cells to the ferroptosis inducer RSL3. In all cases, RSL3-mediated cell death could be blocked by the antioxidant Ferrostatin-1, confirming ferroptosis as the mechanism of cell death. Knocking out ATGL also augmented the ferroptosis inducer-mediated increase in lipid peroxides as indicated by the increased ratio of oxidized to non-oxidized C11-BODIPY 581/591. With regards to the mechanism for the sensitivity of ATGL KO to ferroptosis induction, previous research has established that the enzyme long-chain acyl-CoA synthetase 4 (ACSL4) is universally essential to facilitate ferroptosis. More specifically, ATGL(PNPLA2) was found to inversely correlate with ACSL4 in the Taylor et al., the TCGA PanCancer Atlas, and Metastatic Prostate Adenocarcinoma (SU2C/PCF Dream Team) datasets in both primary and metastatic tumors. qPCR and western blot analysis of ACSL4 levels further showed that ACSL4 expression is closely tied to the lipase activity of ATGL. Addition of arachidonic acid significantly induced ferroptosis when combined with RSL3 in a dose-dependent manner only in ATGL KO cells. This indicates that PUFAs can render ATGL KO cells even more sensitive to RSL3-induced ferroptosis while cells with functional ATGL remain highly resistant, further reinforcing that ATGL is an essential safeguard of CRPC against ferroptosis. ATGL KO cells also demonstrated sensitivity to the antiandrogen Enzalutamide. The combination of Enzalutamide and RSL3 substantially decreased cell viability in ATGL KO cells as compared to control cells, indicating a strong synergy effect particularly seen in ATGL KO cells. In summary, this work demonstrates that ATGL is an important and novel regulator of ferroptosis in CRPC and supports the use of ferroptosis inducer as a new therapeutic approach in CRPC.

Presentation: 6/2/2024
8398 Non-genomic Effects Of Thyroid Hormones On The Breast Cancer Microenvironment
Authors: Drago Leandro , Shahrivari Shabnam , Schwenk Nathalie , Nelson Peter , Hosseini Hedayatollah , Spitzweg Christine
Published: October 2024

Disclosure: L. Drago: None. S. Shahrivari: None. N. Schwenk: None. P. Nelson: None. H. Hosseini: None. C. Spitzweg: None.

Objective: Mesenchymal stem cells (MSCs) are central players in the genesis of the breast cancer tumor microenvironment and play a role in tumor initiation, progression, invasion, metastasis, angiogenesis as well as resistance to treatment. There is increasing evidence for an association between thyroid function and breast cancer risk. Thyroid hormone effects mediated through the αvβ3 integrin, a thyroid hormone receptor, are proposed as a pathophysiologic link to this observation. Methods: To evaluate the migratory behavior of MSCs in the presence or absence of thyroid hormone treatment in response to tumor-derived signals, a 3D migration assay was performed. MSCs pretreated with T3 (1nM) or T4 (1μM) with or without tetrac (100nM) (T4 analog, specific inhibitor of αvβ3 integrin-mediated thyroid hormone action) for 24 h were subjected to a gradient between serum-free medium and serum-free conditioned medium (CM) from five different breast cancer cell lines representative of different breast cancer subtypes including T47D as Luminal B, MCF7 as Luminal A, BT-474 and MDA-MB-453 as HER2, and MDA-MB-231 as Triple negative subtype. Results: MSCs subjected to a gradient between CM derived from each breast cancer cell line and serum-free medium showed directed chemotaxis towards tumor-CM with a significantly increased forward migration index (FMI) and center of mass (CoM). This migratory behavior was significantly enhanced upon treatment with T3 or T4. The cellular migration towards tumor-CM of MDA-MB-453, BT-474, and T47D was more effective upon MSC treatment with T3, but less so with T4. MSCs treated with T4 showed a better migratory performance towards the CM of MCF7 and MDA-MB-231. Except for T47D-CM, additional treatment with tetrac inhibited the enhanced effects of T3 and T4 on MSC migration demonstrating that this effect is mediated through αvβ3 integrin. Conclusion: Our preliminary in vitro data on the effects of thyroid hormones T3 and T4, and the thyroid hormone metabolite tetrac on MSC migration shows a distinct behaviour of MSCs in the presence of either T3 or T4 depending on the breast cancer cell subtype, suggesting a role of non-genomic, integrin αvβ3-mediated thyroid hormone action on MSC biology within the breast tumor microenvironment that warrants further investigation.

Presentation: 6/3/2024
8592 Parathyroid Carcinoma: A Rare Cause of Primary Hyperparathyroidism
Authors: Koshy S E , Mulcahy C F , Kothari P S , Jacobi E M , Cubb T D
Published: October 2024

Disclosure: S.E. Koshy: None. C.F. Mulcahy: None. P.S. Kothari: None. E.M. Jacobi: None. T.D. Cubb: None.

Introduction: Parathyroid carcinoma (PC) is a rare malignancy that accounts for <1% of cases of primary hyperparathyroidism (PHPT). Patients often present with symptoms of hypercalcemia, serum calcium (Ca) >14 mg/dL, large tumor size, and a very high parathyroid hormone (PTH) level. We report a case of an asymptomatic patient with incidentally found hypercalcemia consistent with PHPT who was ultimately diagnosed with PC. Clinical Case: A 31yo male was found to have elevated serum Ca of 12.7 mg/dL (8.6-10.3 mg/dL) on labs obtained during routine physical exam. He had no known significant medical or family history and notably had no laboratory evaluation within the prior 10 years. He denied constipation, polyuria, confusion, depression, bone pain, and history of fractures or nephrolithiasis. Workup showed an inappropriately elevated PTH of 505 pg/mL (16-77 pg/mL). Neck ultrasound demonstrated a left inferior 3.9 cm complex thyroid nodule. Sestamibi scan confirmed increased uptake in the inferior left thyroid. Left neck exploration was performed. Intraoperatively, a 3.7 cm left parathyroid mass weighing 13.0 grams was encountered and excised in an en bloc fashion. The left superior parathyroid gland was evaluated and found to be normal. Intraoperative PTH level decreased from 529 pg/mL to 48 pg/mL 10 minutes after excision. Left hemithyroidectomy was not performed. Surgical pathology revealed PC with lymphovascular invasion, suspected capsular invasion, and negative margins. Immunohistochemical staining showed a Ki67 proliferation index up to 5% and complete loss of nuclear staining for parafibromin. Next generation sequencing demonstrated a somatic CDC73 p.L8fs mutation, tumor mutational burden 4.7m/MB, and stable microsatellite instability. Germline testing was negative for a CDC73 mutation. Postoperative staging did not demonstrate evidence of metastatic disease in the neck or chest. Serum Ca remained within normal limits. After multidisciplinary discussion, no further surgical intervention was recommended and plan was for ongoing biochemical and imaging surveillance. Conclusion: Though rare, PC should be considered as a cause of PHPT. The primary treatment is complete surgical resection. Unfortunately, there is a high rate of recurrence, >50%, with most occurring 2-5 years after initial surgery with a median overall survival of 14 years. Thus, long-term surveillance is of utmost importance. Treatment of recurrent disease is surgical resection when feasible as well as medical management of hypercalcemia. Further research is needed to better understand the role of targeted systemic therapy in addition to immunotherapy. PC is most commonly sporadic but can be hereditary, thus genetic evaluation is recommended. Given its rarity and complexity, PC is best managed in a multidisciplinary setting.

Presentation: 6/1/2024
7508 Primary Hyperparathyroidism Caused By A CDC73-Related Atypical Parathyroid Tumor
Authors: Cardenas Ramiro , Tariq Sarah , Habibi Roshanak , Ebrahimi Neda , Astiazaran-Symonds Esteban
Published: October 2024

Disclosure: R. Cardenas: None. S. Tariq: None. R. Habibi: None. N. Ebrahimi: None. E. Astiazaran-Symonds: None.

Background: Primary hyperparathyroidism (PHPT) is a common endocrine disease, causes include: parathyroid adenomas (80-85%), parathyroid hyperplasia (10-15%), atypical parathyroid adenomas (APA) (1.2 %) and parathyroid carcinomas (PC) (1%). APA share many anatomic and histopathologic features with PC making the distinction between the two challenging. Although most are sporadic, some APA are caused by germline mutations in the CDC73 gene, which is associated with hyperparathyroidism-jaw tumor (HPT-JT) syndrome PC and familial isolated PHPT with APA. Clinical Case: A 42-year-old female presented to the clinic for evaluation of recurrent PHPT. She was diagnosed at age 22 when she experienced fatigue, polydipsia with hypercalcemia (12.9mg/dl). She underwent superior bilateral parathyroidectomy with pathology consistent with parathyroid adenoma. Twenty years later, symptoms recurred and tests showed hypercalcemia (13.0 mg/dl), elevated PTH (252 pg/dl), kidney function preserved (GFR: 82.5 ml/min), normal vitamin D 25 OH (31 ng/dl). Patient denied history of nephrolithiasis or fractures. Family history was positive for kidney stones in father and siblings, also history of a jaw tumor in niece. Sestamibi scan showed a left inferior parathyroid adenoma. Patient underwent resection of the adenoma; pathology revealed a left parathyroid adenoma with atypical parathyroid tumor, >95% cellularity with cytologic features concerning for malignancy, prominent macronucleoli, necrosis, elevated mitotic activity and Ki67 with 15% tumor cells without vascular invasion. Post-op Calcium and PTH normalized (9.6 mg/dl and 10.8 pg/ml, respectively). Genetic testing via multi-gene panel identified a whole gene deletion of CDC73, consistent with hyperparathyroidism-jaw tumor syndrome. Panoramic jaw x-rays did not show jaw tumors. Genetic testing for family members is underway. Conclusion: Although somatic mutations in CDC73 are frequently found in sporadic APA and PC, germline mutations are a rare cause of PHPT associated with these tumors. Histopathological examination is necessary to confirm the diagnosis of APA and to differentiate it from PC, which has a recurrence rate >50%. APA should be treated as a “tumor of uncertain malignant potential” and needs to be carefully and periodically followed up with measurement of Ca, PTH and vitamin D. Confirmation of a CDC73 mutation by genetic testing helped identify the increased risk for other associated tumors in jaw, kidneys and uterus prompting initiation of surveillance with panoramic jaw x-rays with neck shielding, renal US and pelvis US. Genetic testing of family members will allow timely detection and treatment of individuals at risk.

Presentation: 6/3/2024
7323 Prostatic Acid Phosphatase Is Negatively Regulated By Androgens And Persists In Castration-Resistant Prostate Cancer
Authors: Kirschenbaum Alexander , Cheung Pamela , Yao Shen , Cheung Pamela
Published: October 2024

Disclosure: A. Kirschenbaum: None. P. Cheung: None. S. Yao: None. P. Cheung: None.

Background: Prostate cancer (PCa) is the most common cancer and second leading cause of cancer death in American men. Most patients with metastatic PCa respond initially to androgen deprivation therapy (ADT) but the majority will progress to lethal, metastatic, castrate-resistant PCa (mCRPC). The identification of markers of mCRPC that are not regulated or negatively regulated by androgens can serve as markers and therapeutic targets in mCRPC. We hypothesized that prostatic acid phosphatase (PAP), a protein phosphatase and 5’ectonucleotidase that is expressed in both the cytoplasm and transmembrane (TM-PAP) of PCa cells, is negatively regulated by androgen signaling and can serve as a therapeutic target. Methods: PAP protein expression was assessed by immunohistochemistry (IHC) in PCa cell line spheroids (VCaP, 22Rv1, LNCaP, C42B) +/- androgen addition as well as in LNCaP s.c. xenografts +/- castration. Protein expression of PAP was assessed with western blotting in PCa cell lines after treatment with androgens (DHT) and anti-androgen (enzalutamide). Results: In spheroids derived from PCa cell lines, there is some IHC expression of PAP with the strongest staining in VCaP and 22Rv1 spheroids. DHT decreased PAP IHC expression in all spheroids. LNCaP and VCaP s.c. xenografts demonstrated that castration decreased tumor growth rates but that in castrate as well as control tumors PAP expression persisted. All forms of PAP including TM-PAP are expressed in VCaP cell line and were negatively regulated by androgen addition. Conclusions: The identification of markers of mCRPC that are not regulated or are negatively regulated by androgen could help identify recalcitrant tumor cells and mount targeted delivery of therapeutic agents. In several androgen sensitive PCa cell lines, DHT addition decreased PAP expression in spheroids. In vivo, PAP expression persists after castration in spite of decreases in tumor growth rates. Finally, DHT decreases and enzalutamide restores PAP expression in vitro. These data demonstrate that PAP is a more progenitor cell marker in PCa that persists after castration and may be targeted in castration-resistant disease.

Presentation: 6/3/2024