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Debora L S Danilovic, George B Coura-Filho, Giulianna M Recchia, Luciana A Castroneves, Suemi Marui, Carlos A Buchpiguel, Ana O Hoff, and Peter Kopp

Radioiodine (RAI) is selectively recommended for intermediate-risk differentiated thyroid carcinomas (DTC). The information gleaned from pretherapy stimulated thyroglobulin levels (sTg) and diagnostic 131I whole-body scans (DxWBS) to guide therapy remains controversial. The present study aimed at evaluating the impact of preablation sTg and DxWBS in the management of intermediate-risk DTC. A retrospective analysis of 301 intermediate-risk DTC patients submitted to total thyroidectomy and RAI therapy was performed. Pretherapy sTg and DxWBS and post-therapy WBS (RxWBS) findings were analyzed and compared to outcomes. Fifty-two patients (17.3%) had metastases diagnosed by DxWBS and/or RxWBS. The DxWBS identified 10.6% of patients with functioning metastases, including unexpected distant metastases. If combined with SPECT-CT, DxWBS detected RAI-avid metastases more frequently, particularly lymph node metastases (13.1% vs 4.2% planar WBS, P = 0.015). The DxWBS findings modified patient management in 8.3%. A pretherapy sTg <1 ng/mL was associated with a low false-negative rate for the presence of metastases (5.2%), and its performance in excluding metastasis was improved by a negative DxWBS (2.7% of patients with both negative exams had metastases in RxWBS). A sTg <1 ng/mL predicted statistically significant lower rates of recurrent/persistent disease and biochemical/structural incomplete responses. In conclusion, preablation sTg and DxWBS contribute to the detection of unknown or persistent metastatic disease in intermediate-risk DTC patients. A sTg <1 ng/mL in combination with a negative DxWBS is highly suggestive of the absence of remaining malignant disease, and one may consider deferring RAI ablation if both exams are negative. A stunning effect is rarely observed and it does not impair proper treatment of metastases.

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Razan Abou Ziki, Romain Teinturier, Yakun Luo, Catherine Cerutti, Jean-Marc Vanacker, Coralie Poulard, Thomas Bachelot, Mona Diab-Assaf, Isabelle Treilleux, Chang Xian Zhang, and Muriel Le Romancer

Menin, encoded by the MEN1 gene, has been identified as a critical factor regulating ESR1 transcription, playing an oncogenic role in ER+ breast cancer (BC) cells. Here, we further dissected the consequences of menin inactivation in ER+ BC cells by focusing on factors within two major pathways involved in BC, mTOR and MYC. MEN1 silencing in MCF7 and T-47D resulted in an increase in phosphor-p70S6K1, phosphor-p85S6K1 and phosphor-4EBP1 expression. The use of an AKT inhibitor inhibited the activation of S6K1 and S6RP triggered by MEN1 knockdown (KD). Moreover, MEN1 silencing in ER+ BC cells led to increased formation of the eIF4E and 4G complex. Clinical studies showed that patients with menin-low breast cancer receiving tamoxifen plus everolimus displayed a trend toward better overall survival. Importantly, MEN1 KD in MCF7 and T-47D cells led to reduced MYC expression. ChIP analysis demonstrated that menin bound not only to the MYC promoter but also to its 5’ enhancer. Furthermore, E2-treated MEN1 KD MCF7 cells displayed a decrease in MYC activation, suggesting its role in estrogen-mediated MYC transcription. Finally, expression data mining in tumors revealed a correlation between the expression of MEN1 mRNA and that of several mTORC1 components and targets and a significant inverse correlation between MEN1 and two MYC inhibitory factors, MYCBP2 and MYCT1, in ER+ BC. The current work thus highlights altered mTORC1 and MYC pathways after menin inactivation in ER+ BC cells, providing insight into the crosstalk between menin, mTORC1 and MYC in ER+ BC.

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Charlotte Nys, Yu-Lun Lee, Heleen Roose, Freya Mertens, Ellen De Pauw, Hiroto Kobayashi, Raf Sciot, Marie Bex, Georges Versyck, Steven De Vleeschouwer, Johannes Van Loon, Emma Laporte, and Hugo Vankelecom

Pituitary tumorigenesis is highly prevalent and causes major endocrine disorders. Hardly anything is known on the behavior of the local stem cells in this pathology. Here, we explored the stem cells’ biology in mouse and human pituitary tumors using transcriptomic, immunophenotyping and organoid approaches. In the prolactinoma-growing pituitary of dopamine receptor D2 knock-out mice, the stem cell population displays an activated state in terms of proliferative activity and distinct cytokine/chemokine phenotype. Organoids derived from the tumorous glands’ stem cells recapitulated these aspects of the stem cells’ activation nature. Upregulated cytokines, in particular interleukin-6, stimulated the stem cell-derived organoid development and growth process. In human pituitary tumors, cells typified by expression of stemness markers, in particular SOX2 and SOX9, were found present in a wide variety of clinical tumor types, also showing a pronounced proliferative status. Organoids efficiently developed from human tumor samples, displaying a stemness phenotype as well as tumor-specific expression fingerprints. Transcriptomic analysis revealed fading of cytokine pathways at organoid development and passaging, but their reactivation did not prove capable of rescuing early organoid expansion and passageability arrest. Taken together, our study revealed and underscored an activated phenotype of the pituitary-resident stem cells in tumorigenic glands and tumors. Our findings pave the way to defining the functional position of the local stem cells in pituitary tumor pathogenesis, at present barely known. Deeper insight can lead to more efficient and targeted clinical management, currently still not satisfactorily.

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Ziwei Zhang, Menglian Li, Jianjun Wang, Mengsi Liu, Huan Chen, Yuan Lou, Yijie Wang, Qi Sun, Dalong Zhu, Ping Li, and Yan Bi

Adrenocortical carcinoma (ACC) is a rare malignancy with a poor prognosis and challenging management. The present study aimed to investigate the expression of programmed death ligand-1 (PD-L1) and V-domain Ig-containing suppressor of T cell activation (VISTA) in ACC and their associations with clinicopathological features and survival outcomes. Immunohistochemistry was performed on formalin-fixed paraffin-embedded specimens from 54 ACC patients. Chi-square/Fisher’s exact tests or independent samples t/Mann–Whitney U tests were performed to assess correlations between immunoscores and clinicopathological parameters. The Kaplan–Meier method and Cox regression were conducted for survival analysis and to identify independent predictors of overall (OS) and disease-free (DFS) survival. Results showed that VISTA was expressed in tumor cells (TCs) and tumor-infiltrating immune cells (TICs) in 81.5% (44/54) and 40.7% (22/54) of the patients, respectively. PD-L1 positivity was found in either TCs or TICs in 11.1% (6/54) of the patients. Patients with positive VISTA expression in TCs had a higher tumor stage (56.9% vs 20%, P  = 0.036) and Ki-67 index (30.50 ± 23.51% vs 14.76 ± 11.75%, P  = 0.006). However, PD-L1 positivity in either TCs or TICs had no association with patient clinicopathological features. A higher VISTA expression intensity, a larger area and a higher immunoscore were associated with increased risks of disease progression and overall mortality, but PD-L1 expression in TCs or TICs was not associated with OS or DFS. In conclusion, positive TC VISTA expression was correlated with pathological parameters related to malignancy in ACC patients. This finding provides novel evidence of the value of VISTA, in addition to PD-L1, as an immunotherapeutic target in ACC.

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Mirela Diana Ilie, Alexandre Vasiljevic, Emmanuel Jouanneau, and Gérald Raverot

Once temozolomide has failed, there is no recommended treatment option for pituitary carcinomas and aggressive pituitary tumors. Immune-checkpoint inhibitors (ICIs) represent the most recent therapeutic avenue, having raised hope with the publication of the first successful case in 2018. Here, we present an overview of immunotherapy in pituitary carcinomas and aggressive pituitary tumors, starting with the rationale for using ICIs and the implications of tumor-infiltrating lymphocytes in anterior pituitary tumors, followed by a systematic review of all published cases, analyzing both treatment response and potential predictors of response and finishing with research and clinical perspectives. Seven corticotroph and four lactotroph tumors have been so far treated with ICIs. Corticotroph tumors showed radiological partial response in 57% of cases, followed by stable disease in 29% of cases, which was accompanied by biochemical partial or complete response in 83% of cases. Half of lactotroph tumors showed radiological complete or partial response, accompanied by biochemical complete response in 33% of the cases. In the case of a dissociate response, continuation of immunotherapy combined with local treatment represents a good option. At this time, a high tumor mutational burden appears to be the most promising predictive marker of response. MMR deficiency does not guarantee a response. Negative PD-L1 staining should not preclude ICIs administration. Therefore, ICIs are a promising option after temozolomide failure. This review highlights key clinical aspects that can already be implemented into practice and also discusses tumor biology concepts and perspectives expected to improve immunotherapy outcomes.

Open access

Anna Angelousi, Aimee R Hayes, Eleftherios Chatzellis, Gregory A Kaltsas, and Ashley B Grossman

Medullary thyroid carcinoma (MTC) is a rare malignancy comprising 1–2% of all thyroid cancers in the United States. Approximately 20% of cases are familial, secondary to a germline RET mutation, while the remaining 80% are sporadic and also harbour a somatic RET mutation in more than half of all cases. Up to 15–20% of patients will present with distant metastatic disease, and retrospective series report a 10-year survival of 10–40% from time of first metastasis. Historically, systemic therapies for metastatic MTC have been limited, and cytotoxic chemotherapy has demonstrated poor objective response rates. However, in the last decade, targeted therapies, particularly multitargeted tyrosine kinase inhibitors (TKIs), have demonstrated prolonged progression-free survival in advanced and progressive MTC. Both cabozantinib and vandetanib have been approved as first-line treatment options in many countries; nevertheless, their use is limited by high toxicity rates and dose reductions are often necessary. New generation TKIs, such as selpercatinib or pralsetinib, that exhibit selective activity against RET, have recently been approved as a second-line treatment option, and they exhibit a more favourable side-effect profile. Peptide receptor radionuclide therapy or immune checkpoint inhibitors may also constitute potential therapeutic options in specific clinical settings. In this review, we aim to present all current therapeutic options available for patients with progressive MTC, as well as new or as yet experimental treatments.

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Ophélie Delcorte, Julie Craps, Siam Mahibullah, Catherine Spourquet, Ludovic D’Auria, Patrick Van Der Smissen, Chantal Dessy, Etienne Marbaix, Michel Mourad, and Christophe E Pierreux

Differential diagnosis of thyroid cancer and benign nodules is still one of the most challenging issues in the field of endocrinology. To overcome overdiagnosis of papillary thyroid carcinomas (PTC) and the consecutive overtreatment of multinodular diseases, the search for easily accessible, sensitive and accurate biomarkers is critical. Several micro-RNAs (miRNAs) freely circulating in peripheral blood or enclosed in extracellular vesicles (EVs) have been proposed as potential biomarkers from non-invasive liquid biopsies. However, protocols are rarely comparable and conflicting data exist in the literature. In this work, we aimed to assess the diagnostic value of six micro-RNAs by comparing their expression in thyroid tissue to their abundance in bulk plasma and in plasma-EVs, before and after thyroid surgery. Plasma-EVs were isolated using a sequential density- and size-based fractionation, followed by in-depth characterization, confirming EV purity. Micro-RNA levels were measured by RT-qPCR in thyroid tissue, plasma and plasma-EVs. Among the six candidates, only miR-146b-5p and miR-21a-5p displayed a significant differential abundance in purified plasma-derived EVs from patients with PTC and benign disease. However, no difference could be demonstrated in bulk plasma through our cohort of patients. Overall, our work supports the use of a well-defined protocol of plasma-EV miRNAs purification for biomarker discovery, rather than the use of freely circulating miRNAs in bulk plasma. Our work also demonstrates that standardized pre-analytical and analytical procedures as well as optimized EV-miRNAs detection methods are essential.

Free access

Feng Xu, Yali Ling, Jingjing Yuan, Qin Zeng, Lusha Li, Dexing Dai, Xuedi Xia, Ruoman Sun, Ran Zhang, and Zhongjian Xie

Differentiated thyroid carcinoma (DTC) is the most common endocrine malignancy and highly expresses the receptor for 1,25-dihydroxyvitamin D (1,25(OH)2D). However, it is unclear whether 1,25(OH)2D regulates DTC proliferation and differentiation. Here, we found that 1,25(OH)2D3 inhibited proliferation but not differentiation of the DTC cells. Notably, CYP27B1was elevated in DTC cells and 25-hydroxyvitamin D3 (25(OH)D3) reduced DTC cell proliferation. Knockdown of VDR did not affect the anti-proliferative effects of 1,25(OH)2D3. However, knockdown of CCAAT enhancer-binding protein β (C/EBPβ)abolished 1,25(OH)2D3-suppressed DTC cell proliferation. In addition, 1,25(OH)2D3 induced phosphorylation and translocation of C/EBPβto the nucleus from the cytoplasm. However, inhibition of p38 mitogen-activated protein kinases (MAPK) abrogated 1,25(OH)2D3-induced phosphorylation and nuclear translocation of C/EBPβas well as 1,25(OH)2D3-suppressed DTC cell proliferation. Knockdown of C/EBPβreduced the expression of Notch3. Knockdown of Notch3 blocked 1,25(OH)2D3-suppressed DTC cell proliferation. In the DTC cell-derived xenograft SCID mouse, knockdown of C/EBPβmarkedly increased tumor growth and proliferation and decreased apoptosis. In DTC patients, C/EBPβwas predominantly located in the cytoplasm of DTC cells in the tumor tissue when compared with adjacent non-cancerous tissue in which C/EBPβis located in the nucleus. In conclusion, C/EBPβstimulated Notch3signaling via the p38 MAPK-dependent pathway mediates the inhibitory effect of 1,25(OH)2D on DTC cell proliferation.

Free access

Yeon-Sook Choi, Hyemi Kwon, Mi-Hyeon You, Tae Yong Kim, Won Bae Kim, Young Kee Shong, Min Ji Jeon, and Won Gu Kim

Dabrafenib is a BRAF kinase inhibitor approved for treatment of BRAF-mutated anaplastic thyroid carcinoma (ATC) in combination with trametinib. Erlotinib is a tyrosine kinase inhibitor of EGF receptor (EGFR). We evaluated effects of dabrafenib and erlotinib combination treatment on ATC cells in vitro and in vivo. Cell proliferation, colony formation, apoptosis, and migration of ATC cells harboring a BRAF mutation (BHT101, 8505C, and SW1736) were evaluated after treatment with dabrafenib in combination with erlotinib or trametinib. The changes in activation of mitogen extracellular kinase (MEK) and extracellular signal-related kinase (ERK) signaling were also evaluated by Western blot analysis. Effects of these combinations were also evaluated using an in vivo xenograft model. First, we detected EGFR activation in dabrafenib-resistant SW1736 cells using a phospho-receptor tyrosine kinase array. A dabrafenib and erlotinib combination synergistically inhibited cell proliferation, colony formation, and migration, with an induction of apoptotic cell death in all three ATC cells, compared with dabrafenib or erlotinib alone. This synergistic effect was comparable with a dabrafenib and trametinib combination. The dabrafenib and erlotinib combination effectively inhibited phosphorylated (p)-MEK, p-ERK, and p-EGFR expressions compared with dabrafenib or erlotinib alone, while the dabrafenib and trametinib combination only inhibited p-MEK and p-ERK expressions. The dabrafenib with erlotinib or trametinib combinations also significantly suppressed tumor growth and induced apoptosis in a BHT101 xenograft model. The dabrafenib and erlotinib combination could be a potential novel treatment regimen to overcome drug resistance to dabrafenib alone in patients with BRAF-mutated ATC.

Free access

Matthew H Kulke, Fang-Shu Ou, Donna Niedzwiecki, Lucas Huebner, Pamela Kunz, Hagen F Kennecke, Edward M Wolin, Jennifer A Chan, Eileen M O’Reilly, Jeffrey A Meyerhardt, and Alan Venook

Treatment with the MTOR inhibitor everolimus improves progression-free survival (PFS) in pancreatic neuroendocrine tumors (pNETs), but it is not known if the addition of a VEGF pathway inhibitor to an MTOR inhibitor enhances antitumor activity. We performed a randomized phase II study evaluating everolimus with or without bevacizumab in patients with advanced pNETs. One hundred and fifty patients were randomized to receive everolimus 10 mg daily with or without bevacizumab 10 mg/kg i.v. every 2 weeks. Patients also received standard dose of octreotide in both arms. The primary endpoint was PFS, based on local investigator review. Treatment with the combination of everolimus and bevacizumab resulted in improved progression-free survival compared to everolimus (16.7 months compared to 14.0 months; one-sided stratified log-rank P  = 0.1028; hazard ratio (HR) 0.80 (95% CI 0.56–1.13)), meeting the predefined primary endpoint. Confirmed tumor responses were observed in 31% (95% CI 20%, 41%) of patients receiving combination therapy, as compared to only 12% (95% CI 5%, 19%) of patients receiving treatment with everolimus (P = 0.0053). Median overall survival duration was similar in the everolimus and combination arm (42.5 and 42.1 months, respectively). Treatment-related toxicities were more common in the combination arm. In summary, treatment with everolimus and bevacizumab led to superior PFS and higher response rates compared to everolimus in patients with advanced pNETs. Although the higher rate of treatment-related adverse events may limit the use of this combination, our results support the continued evaluation of VEGF pathway inhibitors in pNETs.