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Sylvia L Asa and Shereen Ezzat

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Maria P Yavropoulou, Marina Tsoli, Konstantinos Barkas, Gregory Kaltsas, and Ashley Grossman

Non-functioning pituitary adenomas, recently alternatively termed pituitary neuroendocrine tumours (NFpitNETs), are mostly benign neoplasms that are not associated with a hormonal hypersecretory syndrome. The clinical spectrum of NFpitNETs varies from completely asymptomatic to the development of panhypopituitarism and manifestations attributed to mass effects on nearby structures. NFpitNETs follow generally an indolent course, but in 5–10% of cases they exhibit more aggressive behaviour, characterised by rapid growth, invasiveness and early recurrence. The initial size of the adenoma, the presence of symptoms and the histological subtype are related to the natural course of NFpitNETs. Active surveillance is usually the strategy of choice in the case of an asymptomatic NFpitNET, while surgical resection is recommended in case of visual and/or neurological abnormalities or rapid tumour growth. Based on previous and emerging data, approximately 50% of patients show tumour growth, while 20% of patients with NF-macroadenomas on active surveillance may require further intervention during a follow-up period of 7 years. Adjuvant radiotherapy is usually considered for large residual tumours or recurrent and/or aggressive adenomas, but there is evidence that medical therapy, especially with cabergoline, can occasionally be beneficial, whereas newer molecular agents are under investigation. Thus, while highly effective medical therapy is awaited, a move towards a more conservative approach seems appropriate, at least until we have better molecular markers of progressiveness.

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Isadora Ramos-Andrade, João Moraes, Renata Machado Brandão-Costa, Simone Vargas da Silva, Antônio de Souza, César da Silva, Mariana Renovato-Martins, and Christina Barja-Fidalgo

Obesity is a chronic low-grade inflammatory condition that strongly impacts breast cancer. Aside from inflammatory mediators, obese adipose tissue (AT) secretes high amounts of extracellular vesicles (EVs), which are capable of transferring molecules to target cells and promoting cell-to-cell communication. Here, we investigated how soluble mediators and EVs secreted by human obese AT influence MCF-7 and MDA-MB-231 mammary adenocarcinoma cell lines by modulating cell proliferation, migration, invasion, and signaling pathways. Both cell lineages were stimulated with conditioned media (CM) or EVs obtained from cultures of AT explants collected from lean or obese individuals who underwent plastic or bariatric surgeries, respectively. EVs derived from obese AT increased the proliferative potential of both cell lines and further potentiated the migratory and invasive properties of MDA-MB-231 cells. The proliferative effects of CM and EVs on MCF-7 cells were dependent on ERK/MAPK pathway activation, while the migration and invasiveness of MDA-MB-231 cells were dependent on PI3K/AKT pathway activation. Furthermore, CM derived from obese AT potentiated the pro-angiogenic effect of MDA-MB-231 on endothelial cells. We also detected that EVs derived from obese AT were enriched in leptin and bioactive matrix metallopeptidase 9 (MMP9), and stimulation of MDA-MD-231 cells with those EVs or CM derived from obese AT potentiated the release of MMP9 by those cells. Our data indicate that obese AT secretes molecules and EVs with pro-tumoral activities capable of increasing breast cancer cell malignancy and provide strong evidence of the key role of AT-derived EV signaling in the tumor microenvironment.

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Xhesika Shanja-Grabarz, Anouchka Coste, David Entenberg, and Antonio Di Cristofano

Genetically engineered and orthotopic xenograft mouse models have been instrumental for increasing our understanding of thyroid cancer progression and for the development of novel therapeutic approaches in a setting that is more physiologically relevant than the classical subcutaneous flank implants. However, the anatomical location of the thyroid gland precludes a non-invasive analysis at the cellular level of the interactions between tumor cells and the surrounding microenvironment and does not allow a real-time evaluation of the response of tumor cells to drug treatments. As a consequence, such studies have generally only relied on endpoint approaches, limiting the amount and depth of the information that could be gathered. Here we describe the development of an innovative approach to imaging specific aspects of thyroid cancer biology, based on the implantation of a permanent, minimally invasive optical window that allows high-resolution, multi-day, intravital imaging of the behavior and cellular dynamics of thyroid tumors in the mouse. We show that this technology allows visualization of fluorescently tagged tumor cells both in immunocompetent, genetically engineered mouse models of anaplastic thyroid cancer (ATC) and in immunocompromised mice carrying orthotopic implanted human or mouse ATC cells. Furthermore, the use of recipient mice in which endothelial cells and macrophages are fluorescently labeled allows the detection of the spatial and functional relationship between tumor cells and their microenvironment. Finally, we show that ATC cells expressing a fluorescent biosensor for caspase 3 activity can be effectively utilized to evaluate, in real-time, the efficacy and kinetics of action of novel small molecule therapeutics. This novel approach to intravital imaging of thyroid cancer represents a platform that will allow, for the first time, the longitudinal, in situ analysis of tumor cell responses to therapy and of their interaction with the microenvironment.

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Chunyan Wu, Huijian Zhang, Xiaochun Lin, Yanmei Zeng, Yudan Zhang, Xiaoqin Ma, Yaoming Xue, and Meiping Guan

Studies have shown that pheochromocytoma (PHEO) is associated with glucose intolerance and decreased insulin sensitivity. In adipocytes, pyruvate dehydrogenase kinase 4 (PDK4) is involved in glucose uptake. However, very little is known about the role of PDK4 in the insulin signaling pathway in the adipose tissue of PHEO patients. We analyzed the expression of adipokines, oxidative stress-related genes, PDK4, phosphorylated AMPK (pAMPK) and phosphorylated IRS1 (pIRS1) in the periadrenal adipose tissue (peri-A) of patients with PHEO and non-functioning adrenal adenoma (NFA). We also investigated the effects of epinephrine on PDK4, pAMPK and pIRS1 in human stromal vascular fraction (SVF) cells, mouse 3T3-L1 preadipocytes and brown preadipocytes. PHEO patients had higher mRNA levels of PGC1α, C/EBPα, C/EBPβ, COXII and AP2 and lower mRNA levels of PPARγ in their peri-A than NFA patients. Decreased pAMPK and increased PDK4 and pIRS1 were observed in the peri-A of PHEO patients. PHEO patients also had significantly higher NOX4 protein expression and lower Nrf2 and HO-1 protein expression in their peri-A than NFA patients. In vitro, epinephrine treatment upregulated PDK4 expression, inhibited AMPK phosphorylation and enhanced IRS1 phosphorylation. The knockdown of PDK4 by siRNA upregulated pAMPK and downregulated pIRS1. In conclusion, PDK4 may play an essential role in hypercatecholamine-induced insulin resistance in the periadrenal adipose tissues of PHEO patients.

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James F Powers, Brent Cochran, James D Baleja, Hadley D Sikes, Andrew D Pattison, Xue Zhang, Inna Lomakin, Annette Shepard-Barry, Karel Pacak, Sun Jin Moon, Troy F Langford, Kassi Taylor Stein, Richard W Tothill, Yingbin Ouyang, and Arthur S Tischler

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Andrea Gutierrez Maria, Christina Tatsi, Annabel Berthon, Ludivine Drougat, Nikolaos Settas, Fady Hannah-Shmouni, Jerome Bertherat, Fabio R Faucz, and Constantine A Stratakis

Mutations in the protein kinase A (PKA) regulatory subunit type 1A (PRKAR1A) and armadillo repeat-containing 5 (ARMC5) genes cause Cushing‘s syndrome (CS) due to primary pigmented nodular adrenocortical disease (PPNAD) and primary bilateral macronodular adrenocortical hyperplasia (PBMAH), respectively. Between the two genes, ARMC5 is highly polymorphic with several variants in the population, whereas PRKAR1A has very little, if any, non-pathogenic variation in its coding sequence. We tested the hypothesis that ARMC5 variants may affect the clinical presentation of PPNAD and CS among patients with PRKAR1A mutations. In this study, 91 patients with PPNAD due to PRKAR1A mutations were tested for abnormal cortisol secretion or CS and for ARMC5 sequence variants. Abnormal cortisol secretion was present in 71 of 74 patients with ARMC5 variants, whereas 11 of 17 patients negative for ARMC5 variants did not have hypercortisolemia. The presence of ARMC5 variants was a statistically strong predictor of CS among patients with PRKAR1A mutations (P < 0.001). Among patients with CS due to PPNAD, ARMC5 variants were associated with lower cortisol levels at baseline (P = 0.04) and after high dose dexamethasone administration (P = 0.02). The ARMC5 p.I170V variant increased ARMC5 protein accumulation in vitro and decreased viability of NCI-H295 cells (but not HEK 293T cells). PPNAD tissues with ARMC5 variants showed stronger ARMC5 protein expression than those that carried a normal ARMC5 sequence. Taken together, our results suggest that ARMC5 variants among patients with PPNAD due to PRKAR1A defects may play the role of a genetic modifier for the presence and severity of hypercortisolemia.

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Jennifer W Carlisle, Caroline S Jansen, Mehmet Asim Bilen, and Haydn Kissick

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Neil A Bhowmick, Jillian Oft, Tanya Dorff, Sumanta Pal, Neeraj Agarwal, Robert A Figlin, Edwin M Posadas, Stephen J Freedland, and Jun Gong

The current pandemic (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global health challenge with active development of antiviral drugs and vaccines seeking to reduce its significant disease burden. Early reports have confirmed that transmembrane serine protease 2 (TMPRSS2) and angiotensin converting enzyme 2 (ACE2) are critical targets of SARS-CoV-2 that facilitate viral entry into host cells. TMPRSS2 and ACE2 are expressed in multiple human tissues beyond the lung including the testes where predisposition to SARS-CoV-2 infection may exist. TMPRSS2 is an androgen-responsive gene and its fusion represents one of the most frequent alterations in prostate cancer. Androgen suppression by androgen deprivation therapy and androgen receptor signaling inhibitors form the foundation of prostate cancer treatment. In this review, we highlight the growing evidence in support of androgen regulation of TMPRSS2 and ACE2 and the potential clinical implications of using androgen suppression to downregulate TMPRSS2 to target SARS-CoV-2. We also discuss the future directions and controversies that need to be addressed in order to establish the viability of targeting TMPRSS2 and/or ACE2 through androgen signaling regulation for COVID-19 treatment, particularly its relevance in the context of prostate cancer management.

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Douglas Wiseman, James D McDonald, Dhaval Patel, Electron Kebebew, Karel Pacak, and Naris Nilubol

Postoperative hypotension frequently occurs after resection of pheochromocytoma and/or paraganglioma (PPGLs). Epidural anesthesia (EA) is often used for pain control in open resection of these tumors; one of its side effects is hypotension. Our aim is to determine if EA is associated with an increased risk of postoperative hypotension after open resection of PPGLs. We conducted a retrospective review of patients who underwent open resection of PPGLs at the National Institutes of Health from 2004 to 2019. Clinical and perioperative parameters were analyzed by the use of EA. The primary endpoint was postoperative hypotension. Ninety-seven patients (46 female and 51 male; mean age, 38.5 years) underwent open resection of PPGLs and 69 (71.1%) received EA. Patients with EA had a higher rate beta-blocker use (79.7% vs 57.1%, P = 0.041), metastasis (69.6% vs 39.3%, P = 0.011), and were more frequently hypotensive after surgery (58.8% vs 25.0%, P = 0.003) compared to those without EA. Patients with postoperative hypotension had higher plasma normetanephrines than those without (7.3 fold vs 4.1 fold above the upper limit of normal, P = 0.018). Independent factors associated with postoperative hypotension include the use of beta-blockers (HR = 3.35 (95% CI: 1.16–9.67), P = 0.026) and EA (HR = 3.49 (95% CI: 1.25–9.76), P = 0.017). Data from this retrospective study suggest that, in patients with open resection of PPGLs, EA is an independent risk factor for early postoperative hypotension. Special caution is required in patients on beta-blockade. A prospective evaluation with standardized protocols for the use of EA and management of hemodynamic variability is necessary.