bluuebunny/crossref_metadata_2025_split huggingface dataset:
THU476 Role Of Mitochondrial Sirtuins 3 And 5 On Glutamine Addiction In Prostate Cancer Cell
Authors: Hasan Kamrul M , Friedman Theodore C , Chen Wenyong 
Published: October 2023

Abstract
Disclosure: K.M. Hasan: None. T.C. Friedman: None. W. Chen: None.
Myc-transformed and hypoxic cancer cells are sensitive to glutamine deprivation. Reprogramming to glutamine addiction helps to maintain the TCA cycle pool and anaplerosis that provide cancer cells energy and various macromolecules critical for rapid proliferation. However, the mechanism of glutamine addiction has yet to be fully understood. Here we explore the effect of mitochondrial sirtuins (Sirt3 and Sirt5) on glutamine metabolism in prostate cancer (PCa) cell. We used lentiviral-based knockdown or overexpression methods to examine the effect of Sirt3 and Sirt5 on the growth and proliferation of PC3 and LnCap cells. Cells were grown in both regular or glutamine-free liquid and soft agar media to investigate the effect of Sirt3 and Sirt5 on anchorage-dependent or independent growth, respectively. Cells after the knockdown of Sirt3 and Sirt5 were also grown in media supplemented with cell permeable dimethyl ketoglutarate (DMK), an alternative to ketoglutarate to continue the TCA cycle in the absence of active glutamine metabolism. We showed that anchorage-independent growth (AIG) of PCa cells relied on mitochondrial sirtuins (mtSirts). Inhibition of Sirt3 and Sirt5 activity impaired AIG, and the inhibitory effect was rescued by supplying DMK, suggesting the impact of mtSirts on glutamine metabolism. Most intriguing, our results demonstrated that Sirt3 overexpression enhanced AIG, which can be suppressed by knockdown glutamate dehydrogenase (GDH), suggesting that Sirt3 upregulated glutamine metabolism through GDH activation. Indeed, we found that silencing of Sirt3 and Sirt5 induced the acetylation of GDH and decreased the GDH activity. In agreement, we further observed that glutamine was essential for AIG of prostate cancer cells, and the addition of DMK in a glutamine-free medium rescued the growth, implying that PCa cells are addicted to glutamine. Finally, we showed that the knockdown of Sirt3 and Sirt5 impaired the tumorigenicity of PC3 cells in vivo mouse xenograft model. Thus, we concluded that sirtuins-mediated GDH regulation is a crucial process in the metabolic adaptation of PCa cells that can be a therapeutic target.
Presentation: Thursday, June 15, 2023
THU487 Xenograft of VHL-deficient Pancreatic Neuroendocrine Neoplasm Cells - A Novel Low-grade PNEN In Vivo Model
Authors: Telerman Alona , Yossef Yuval , Chmelnik Adiel , Tirosh Amit 
Published: October 2023

Abstract
Disclosure: A. Telerman: None. Y. Yossef: None. A. Chmelnik: None. A. Tirosh: None.
Background: Von Hippel-Lindau (VHL) disease is a familial cancer syndrome caused by a germline mutation in the VHL tumor suppressor gene. Although VHL-related pancreatic neuroendocrine neoplasms (vPNEN) have been studied, their molecular pathogenesis is not fully understood. Aims: To generate a mouse model for studying the mechanisms that promote vPNEN development in vivo. Methods: We induced a frameshift mutation in VHL using the CRISPR/Cas9 technique in the BON1 cell line, originating from high-grade PNEN (FS-BON1). We validated the pseudohypoxic nature of the cells by real-time polymerase chain reaction of VEGF and EPO in FS-BON1 compared to VHL wild-type BON1 (WT-BON1). We compared cell line-derived xenografts (CDXs) growth in athymic Nude-Foxn1nu female mice injected with WT-BON1 (n=9), FS-BON1 (n=9) and media (purified bovine serum, n=5). Tumor diameter and calculated volume and mice weight were recorded weekly. Plasma chromogranin A (CgA) levels were measured in mice sera by ELISA. Results: FS-BON1 showed upregulation of VEGF and EPO compared with WT-BON1, confirming their pseudohypoxic microenvironment. At 14 weeks, 0/9 FS-BON1 CDX reached a volume of 1 cm3 compared with 5/9 of the WT-BON1 group (p=0.03). In time-dependent analysis, FS-BON1-derived xenografts grew significantly slower than WT-BON1 xenografts (p=0.02). No significant differences in CgA serum levels were found between the mice groups. Conclusions: We report a new pseudohypoxic in vivo PNEN model. The pVHL-deficient cells show an unexpected indolent course, suggesting it as a new model for low-grade PNEN. This CDX mouse model can be utilized in further studies to evaluate the mechanism responsible for vPNEN development and for evaluating interventions in low-grade PNEN.
Presentation: Thursday, June 15, 2023
THU491 GRHL2 Overexpression In Breast Cancer Progression
Authors: Zheng Christy , Allen Kaelyn O , Reese Rebecca , Solodin Natalia M , Vera Jessica , Mcilwain Sean , Liu Tianrui , Alarid Elaine T 
Published: October 2023

Abstract
Disclosure: C. Zheng: None. K.O. Allen: None. R. Reese: None. N.M. Solodin: None. J. Vera: None. S. Mcilwain: None. T. Liu: None. E.T. Alarid: None.
Metastasis constitutes the permissive migration and growth of cancerous cells from the primary tumor to a distant location in the body. Epithelial to mesenchymal transition (EMT) is implicated in metastasis as it allows for cells to abandon an epithelial identity, adopt a mesenchymal phenotype, become migratory, and promote tumor progression. Grainyhead-like protein 2 (GRHL2) is a nuclear transcription factor responsible for driving epithelial cell fate. By regulating epithelial differentiation and integrity in estrogen receptor (ER) positive breast cancer, GRHL2 suppresses EMT, and as such, it was long thought to act primarily as a tumor suppressor. However, clinical evidence contradicts its tumor suppressive role in that patients expressing high levels of GRHL2 have a significantly lower probability of long-term recurrence free survival compared to low levels of GRHL2, and high levels of GRHL2 are also associated with high grade tumors. To better understand this discrepancy, a tetracycline (tet) inducible GRHL2 overexpression model in the ER-positive breast cancer MCF7 cell line was developed to assess cancer associated phenotypes and the transition between epithelial and mesenchymal states. Dose response and time course studies were performed to determine optimal GRHL2 induction in our tet-inducible model using immunofluorescent microscopy and Western blot analysis. Gene expression analyses was performed to assess representative genes associated with epithelial and mesenchymal states, and the intermediates between them known as hybrid or partial EMT. Interestingly, immunocytochemistry identified that the overexpression of GRHL2 induces the late EMT marker, vimentin, despite the inhibition of migration in the epithelial dominant MCF7 cell line. Together, these data indicates that GRHL2 overexpression leads to a complex phenotype that cannot be defined by a binary epithelial or mesenchymal state. Further analyses are aimed at understanding the pleiotropic roles GRHL2 plays in ER+ tumor progression.
Presentation: Thursday, June 15, 2023
THU493 The Role Of Liver Receptor Homolog1 (LRH-1) In Regulating Breast Cancer Progression By Modulating The Immune Response
Authors: Wang Yu , Krawczynska Natalia , Bendre Shruti , Duong Bryan , Vidana Gamage Hashni Epa , Nelczyk Adam , Gupta Anasuya Das , Nelson Erik Russell 
Published: October 2023

Abstract
Disclosure: Y. Wang: None. N. Krawczynska: None. S. Bendre: None. H. Vidana Gamage: None. A. Nelczyk: None. A. Das Gupta: None. E.R. Nelson: None.
Breast cancer is the most common type of cancer and the second leading cause of death among American women. While immunotherapy holds much promise, the current FDA-approved immunotherapies are effective for only a subset of patients lacking expression of estrogen receptor, progesterone receptor and HER2, but positive for PD-L1. Thus, there is strong impetus to develop novel ways to engage the immune system.
We have demonstrated that cholesterol metabolism and homeostasis within myeloid cells can either promote or suppress anti-cancer immunity. One of the regulators of cholesterol homeostasis is Liver Receptor Homolog 1 (LRH-1/NR5A2). We have found that elevated LRH-1 expression in breast tumors is associated with an increased survival. LRH-1 is highly expressed in myeloid cells, particularly neutrophils, a major immune population of the tumor microenvironment. Therefore, we hypothesized that LRH-1 plays modulatory roles in myeloid cells, that subsequently impacts breast cancer progression. Specifically, we evaluated the impact of LRH-1 on myeloid cell biology, including NETosis and phagocytosis.
Treatment of neutrophils with an agonist of LRH-1, DLPC, resulted in decreased NETosis, a function of neutrophils previously implicated in recurrence and metastasis. Treatment with an antagonist resulted in increased NETosis. Both the agonist and antagonist exhibited dose-depended effects, strongly suggesting that LRH-1 regulates the process of NETosis.
Macrophage phagocytosis is an important initial step towards antigen presentation and activation of T cells. Bone marrow derived macrophages treated with the LRH-1 antagonist exhibited decreased phagocytosis activity, in a dose dependent manner. Treatment with the agonist (DLPC) did not alter phagocytosis, but this may be because basal phagocytosis was already very high.
Collectively, our data indicate that LRH-1 plays important roles in the regulation of myeloid cell function, including NETosis in neutrophils and phagocytosis in macrophages. Overall, these findings suggest that LRH-1 activity would be beneficial for an anti-cancer immune response, and therefore position LRH-1 as a therapeutic target. Our ongoing studies will assess the role of LRH-1 in other myeloid cell-related functions including efferocytosis, T-cell expansion and differentiation.
Presentation: Thursday, June 15, 2023
THU522 Symptomatic Hypoglycemia As The First Manifestation Of Multiple Endocrine Neoplasia Type 1 (MEN-1): Case Report
Authors: Oliveira Vitória Dupas , Tormin Stephanie Corradini , Dias Bruna Vieira , Scalissi Nilza , Cunha Scalco Renata Da , Olivati Caroline , de Moricz Andre , Szutan Luiz Arnaldo , Lima Jose Viana 
Published: October 2023

Abstract
Disclosure: V.D. Oliveira: None. S.C. Tormin: None. B.V. Dias: None. N. Scalissi: None. R.D. Scalco: None. C. Olivati: None. A. de Moricz: None. L.A. Szutan: None. J.V. Lima: None.
Introduction: MEN-1 is a rare, autosomal dominant syndrome that occurs due to a pathogenic variant of MEN1. The incidence of insulinoma in MEN-1 is relatively rare. 4-6% of patients with insulinoma will develop MEN-1. Unlike sporadic insulinomas that usually develop after the age of 40, MEN-associated insulinoma usually occur before 40 years of age and even sometimes before 20. CASE REPORT: A 26-year-old male patient had a 3-year history of Whipple's triad associated with significant weight gain with a body mass index (BMI) of 33 kg/m² to 58 kg/m² during this period. His father has a metastatic carcinoid tumor, being treated with palliative chemotherapy. Laboratory tests at the time of hypoglycemia were: blood glucose 42mg/dL (RV 75-99), insulin 39 mU/L (RV &lt; 3) and C-peptide 11.6 ng/dL (RV &lt; 0.2). Magnetic resonance imaging (MRI) of pancreas showed 3 hypervascular nodules, the largest in the tail, measuring 3.3 cm, with neuroendocrine characteristics. Distal pancreatectomy, splenectomy and lymphadenectomy were indicated. After surgery, the episodes of hypoglycemia disappeared, with a weight loss of 25 kg. He required postoperative metformin, with satisfactory glycemic control. During the investigation, a prolactinoma was diagnosed (pituitary MRI, which showed a 4 mm adenoma, prolactin 56ng/mL (LR &lt; 25) and hypogonadotrophic hypogonadism), and cabergoline 0.25 mg/week was started. In addition, diagnosis of mild primary hyperparathyroidism (PTH 188 pg/mL and calcium 10.4mg/dL). Parathyroid scintigraphy with 99mTc-MIBI showed increased uptake in the right lower parathyroid. Genetic testing was performed by Next Generation Sequence (NGS) of the MEN1 gene, which was positive for the pathogenic variant c.825-2A&gt;G in heterozygosis in intron 5. A molecular study was performed on the patient's father and sister, which identified the same pathogenic allelic variant in both. Conclusion: We described a rare case of MEN-1 whose first manifestation was insulinoma.
Presentation: Thursday, June 15, 2023
THU524 Combination Of Mustardé Cheek Advancement Flap And Paramedian Forehead Flap As A Reconstructive Option In Basal Cell Carcinoma Of The Nose: A Functional And Aesthetic Alternative
Authors: Solis Pazmiño Andrea Paola , Rocha Carla , Pilatuna Eduardo , Godoy Richard , Garcia Cristhian 
Published: October 2023

Abstract
Disclosure: A.P. Solis Pazmiño: None. C. Rocha: None. E. Pilatuna: None. R. Godoy: None. C. Garcia: None.
Background: Defects resulting from the surgical procedure due to basal cell carcinoma (BCC) may be challenging to reconstruct depending on the size and location. In moderate to large-sized defects, especially in face lesions, a combination of more than one type of flap might be necessary. We present a patient with a large BCC in the nasal region which was successfully closed using a combination of rotation and advancement flaps. The patient showed excellent functional and cosmetic outcomes. Clinical Case: An elderly woman presented to our center with a five-year history of a persistent nasal vestibular lesion. It was treated with multiple cauterizations without a total improvement, until then. There was no associated pain, bleeding, or drainage. She denied family history, risk factors, or systemic diseases associated with this skin pathology. Physical examination revealed a 4 cm x 3 cm desquamated plaque with multiple pustules and a small deep ulcered area on the left nasal vestibule and overlying telangiectasia. A skin biopsy confirmed the clinical suspicion that this patient had nodular basal cell carcinoma (BCC), also known as rodent ulcer. The patient underwent surgery and we sent an intraoperative frozen section (IFS), 6 margins were taken in 10 mm strips each, and two of the seven tissue samples were reported positive. Made do with a double scalpel blade numbered by segments following clockwise order.Meanwhile, the defect reconstruction was done after histopathological examination confirmed tumor-free margins. A local skin flap, a paramedian forehead flap, transferred full-thickness skin and subcutaneous tissue into the surgical defect, which maintained the local blood supply via a vascular pedicle that remained connected to the donor site. Then, the advancement bilateral flap (Mustardé) was slid into the defect where the incisions were made tangentially to the defect to free neighboring tissue, with the wound edge acting as the free margin of the flap. Finally, for the frontal opening graft tissue, we used a pressure dressing on cutaneous grafts using a gauze wad (Brown Curative). Clinical lessons: This case exposes basal cell carcinoma (BCC), the most common skin malignancy with a predilection on sun-exposed areas such as the face. The surgical technical selected was a combination of skin flap techniques such as paramedian forehead flap, and the cheek rotational (Mustardé) flap showed excellent functional and cosmetic outcomes. Also, the oncological accepted margins depend on the risk group and the tumor size. For primary well-demarcated BCCs smaller than 2 cm, in the low-risk group, a safety margin of 3 mm gives satisfactory results.
Presentation: Thursday, June 15, 2023
THU529 Challenges In The Management Of Biochemically Silent Paraganglioma
Authors: Dewan Sandesh , Farooqi Aneeba , Jun John 
Published: October 2023

Abstract
Disclosure: S. Dewan: None. A. Farooqi: None. J. Jun: None.
Biochemically silent Pheochromocytoma and Paraganglioma (PPGL) are rare neuro-endocrine tumors because of which there is low quality evidence and insufficient guidelines for their management. 74-year-old Female was referred to our Endocrine clinic for incidentally discovered Retroperitoneal mass on MRI. On evaluation patient reported having concerns of escalating anxiety, difficult to control HTN and episodic flushing after physical activity in the last one year. A CT abdomen and pelvis with contrast was ordered which showed 1.7 x 1.8 cm mass anterior to the L5 vertebral body just caudal to the aortic bifurcation. The biochemical work up including 24-hour urine Metanephrines (104 ug/24 hr; n 52-341), Normetanephrines (479 ug/24 hr; n 88-444), Total Metanephrines (583 ug/24 hr; n 88-444), 3 Methoxytyramine (166 mcg/24 hr; n &lt;242) was inconclusive. For further evaluation PET CT DOTATATE scan was ordered which showed the lesion to be DOTATAE somatostatin analogue avid, consistent with somatostatin receptor positive neuroendocrine tumor. Patient was scheduled for surgery in 2 weeks and was started on Terazosin in addition to her anti HTN medications Amlodipine, Losartan and HCTZ. The surgery had to be rescheduled due to inadequate blood pressure control. Her amlodipine and Terazosin dosage were gradually increased while the procedure was rescheduled. Eventually she underwent Laparotomy exploration and resection of the lesion. Patient tolerated the procedure well and had no major intra or post operative fluctuations in her blood pressure, heart rate or blood glucose. According to the Endocrine Surgery team, the tumor could not be sufficiently removed since it was immovable during surgery and could not be delineated from the spine. The post-operative CT scan showed nodular lesion at aortic bifurcation slightly increased in soft tissue component from prior CT scan. After discussions with surgery and oncology team, patient opted for imaging surveillance for now and will consider genetic counseling and/or radiation therapy if the tumor increases in size. Untreated PPGL carries a high risk of cardiovascular morbidity and mortality, and some may also be malignant with a propensity to cause mass effects and metastasis. Currently, there are scarce evidence-based studies comparing treatment options in biochemically silent PPGL, and there is no consensus for the most appropriate peri-operative management of biochemically silent PPGL. This case adds to the literature on how a combination of calcium channel blocker and alpha blocker can be used to achieve peri-operative blood pressure and heart rate control with no major side effects. It also demonstrates the importance of functional imaging, especially in clinically or radiologically suspected PPGL, even with a normal biochemical work up. We suggest multi-disciplinary evaluation and individualized management to ensure positive outcomes.
Presentation: Thursday, June 15, 2023
FRI221 A Case Of Pulmonary Embolism Presenting As Adrenal Crisis
Authors: Guntaka Shilpa , Barron Carly , Zhou Ping 
Published: October 2023

Abstract
Disclosure: S. Guntaka: None. C. Barron: None. P. Zhou: None.
Introduction: Adrenal crisis is not a typical presentation for iatrogenic adrenal insufficiency. We present a case of pulmonary embolism (PE) with a history of steroid use, to show the complexity of diagnosing adrenal crisis caused by iatrogenic adrenal insufficiency. Case Presentation: A 19-year-old woman with a history of severe atopic dermatitis, was treated with high dose prednisone for three weeks. One month after completing the course, she presented to the ED with rash, mid-sternal chest pain, dizziness and shortness of breath. Vitals were significant for tachycardia and hypotension. BMP showed Na 129 mEq/L (135-145), K 6.1 mEq/L (3.5-5), glucose 140 mg/dl, BUN 22mg/dL (5-20), and Creatinine 1.25 mg/dl (&lt 1.2). EKG showed peaked T waves and chest X-ray was normal. Adrenal crisis was the initial impression due to the history of steroid use and electrolyte abnormalities. She received hydrocortisone 100 mg IV for 2 doses. Hyperkalemia was treated with a calcium gluconate bolus, albuterol, insulin and glucose. She continued to endorse difficulty breathing, and chest pain, and so other etiologies were considered. A V/Q scan demonstrated multiple v/q mismatched defects in bilateral lung fields, suggestive of PE. She was admitted for anti-coagulation therapy and showed clinical improvement, without additional steroid use. An ACTH stimulation test demonstrated adequate function of the hypothalamic-pituitary-adrenal axis with normal cortisol response. Baseline and post-stimulation androstenedione and 17OHP, aldosterone, plasma renin activity, DHEAS and TFTs were also normal. Extensive work-up for coagulative and autoimmune disorders was unremarkable. The patient was subsequently restarted on oral prednisone for worsening skin disease. Conclusion: Steroid use has been associated with the development of PE. Hyponatremia can be seen among patients with PE, occurring at rates of 21 to 26%.1 In contrast, secondary adrenal insufficiency presents with euvolemic hyponatremia, and uncommonly hypoglycemia. Hyperkalemia is not typically seen. Salt craving, postural dizziness, dehydration are also not common in secondary adrenal insufficiency as mineralocorticoid function is preserved. This case demonstrates the importance of evaluating for additional etiologies in the setting of hyponatremia with electrolyte abnormalities that are not usually seen with secondary adrenal insufficiency. This patient’s initial presentation is more consistent with PE and acute renal insufficiency. Understanding the presentation of iatrogenic adrenal insufficiency is necessary to make the correct diagnosis, and to ensure patients receive appropriate care.
References: 1. Xiao-Yu Zhou, Song-Shi Ni, et, al. Hyponatremia and short-term prognosis of patients with acute pulmonary embolism: A meta-analysis. International Journal of Cardiology. Vol 227, p251-256, January 15, 2017
Presentation: Friday, June 16, 2023