Deregulation of microRNA (miRNA) expression in adrenocortical carcinomas (ACCs) has been documented to have diagnostic, prognostic, as well as functional implications. Here, we evaluated the mRNA expression of DROSHA, DGCR8, DICER (DICER1), TARBP2, and PRKRA, the core components in the miRNA biogenesis pathway, in a cohort of 73 adrenocortical tumors (including 43 adenomas and 30 carcinomas) and nine normal adrenal cortices using a RT-qPCR approach. Our results show a significant over-expression of TARBP2, DICER, and DROSHA in the carcinomas compared with adenomas or adrenal cortices (P<0.001 for all comparisons). Using western blot and immunohistochemistry analyses, we confirmed the higher expression of TARBP2, DICER, and DROSHA at the protein level in carcinoma cases. Furthermore, we demonstrate that mRNA expression of TARBP2, but not DICER or DROSHA, is a strong molecular predictor to discriminate between adenomas and carcinomas. Functionally, we showed that inhibition of TARBP2 expression in human NCI-H295R ACC cells resulted in a decreased cell proliferation and induction of apoptosis. TARBP2 over-expression was not related to gene mutations; however, copy number gain of the TARBP2 gene was observed in 57% of the carcinomas analyzed. In addition, we identified that miR-195 and miR-497 could directly regulate TARBP2 and DICER expression in ACC cells. This is the first study to demonstrate the deregulation of miRNA-processing factors in adrenocortical tumors and to show the clinical and biological impact of TARBP2 over-expression in this tumor type.
Stefano Caramuta, Linkiat Lee, Deniz M Özata, Pinar Akçakaya, Hong Xie, Anders Höög, Jan Zedenius, Martin Bäckdahl, Catharina Larsson, and Weng-Onn Lui
Lucas Leite Cunha, Marjory Alana Marcello, Vinicius Rocha-Santos, and Laura Sterian Ward
Immune checkpoint inhibitors are agents that act by inhibiting the mechanisms of immune escape displayed by various cancers. The success of immune checkpoint inhibitors against several tumors has promoted a new treatment strategy in clinical oncology, and this has encouraged physicians to increase the number of patients who receive the immune checkpoint therapy. In the present article, we review the main concepts regarding immune checkpoint mechanisms and how cancer disrupts them to undergo immune escape. In addition, we describe the most essential concepts related to immune checkpoint inhibitors. We critically review the literature on preclinical and clinical studies of the immune checkpoint inhibitors as a treatment option for thyroid cancer, ovarian carcinoma, pancreatic adenocarcinoma, adrenocortical carcinoma and neuroendocrine tumors. We present the challenges and the opportunities of using immune checkpoint inhibitors against these endocrine malignancies, highlighting the breakthroughs and pitfalls that have recently emerged.
Michael Solarski, Fabio Rotondo, William D Foulkes, John R Priest, Luis V Syro, Henriett Butz, Michael D Cusimano, and Kalman Kovacs
In this review, the importance of the DICER1 gene in the function of endocrine cells is discussed. There is conclusive evidence that DICER1 mutations play a crucial role in the development, progression, cell proliferation, therapeutic responsiveness and behavior of several endocrine tumors. We review the literature of DICER1 gene mutations in thyroid, parathyroid, pituitary, pineal gland, endocrine pancreas, paragangliomas, medullary, adrenocortical, ovarian and testicular tumors. Although significant progress has been made during the last few years, much more work is needed to fully understand the significance of DICER1 mutations.
B Wängberg, A Khorram-Manesh, S Jansson, B Nilsson, O Nilsson, C E Jakobsson, S Lindstedt, A Odén, and H Ahlman
Adrenocortical carcinoma (ACC) is a rare tumour disease with sinister prognosis also after attempts to radical surgery; better prognosis is seen for low-stage tumours. Adjuvant treatment with the adrenolytic drug mitotane has been attempted, but not proven to prevent from recurrence. The drug may offer survival advantage in case of recurrence. The aim of this single-centre study (1979–2007) of 43 consecutive patients was to evaluate the long-term survival after active surgical treatment combined with monitored mitotane (to reduce side effects of the drug). The series is unique, since all patients were offered a period of mitotane as adjuvant or palliative treatment; six patients refused mitotane. Despite a high proportion of high-stage tumours (67%), the complete resection rate was high (77%). The disease-specific 5-year survival was high (64.1%); very high for patients with low-stage tumours without evident relation to mitotane levels. Patients with high-stage tumours had a clear survival advantage with mitotane levels above a threshold of 14 mg/l in serum. The hazard ratio for patients with high mitotane levels versus all patients indicates a significant effect of the drug. The results indicate that adjuvant mitotane may be the standard of care for patients with high-stage ACC after complete resection.
Paola Sperone, Anna Ferrero, Fulvia Daffara, Adriano Priola, Barbara Zaggia, Marco Volante, Daniele Santini, Bruno Vincenzi, Giuseppe Badalamenti, Chiara Intrivici, Sabrina Del Buono, Silvia De Francia, Emmanouil Kalomirakis, Riccardo Ratti, Alberto Angeli, Luigi Dogliotti, Mauro Papotti, Massimo Terzolo, and Alfredo Berruti
Adrenocortical carcinoma (ACC) is a rare neoplasm characterized by poor prognosis. First-line systemic treatments in advanced disease include mitotane, either alone or in combination with chemotherapy. Studies evaluating second-line therapy options have obtained disappointing results. This trial assessed the activity and toxicity of gemcitabine plus metronomic fluoropyrimidines in heavily pretreated advanced ACC patients. From 1998 to 2008, 28 patients with advanced ACC progressing after mitotane plus one or two systemic chemotherapy lines were enrolled. They received a combination of i.v. gemcitabine (800 mg/m2, on days 1 and 8, every 21 days) and i.v. 5-fluorouracil protracted infusion (200 mg/m2/daily without interruption until progression) in the first six patients, or oral capecitabine (1500 mg/daily) in the subsequent patients. Mitotane administration was maintained in all cases. The rate of non-progressing patients after 4 months of treatment was 46.3%. A complete response was observed in 1 patient (3.5%); 1 patient (3.5%) obtained a partial regression, 11 patients (39.3%) obtained a disease stabilization and 15 patients (53.7%) progressed. Treatment was well tolerated, with grade III and IV toxicities consisting of leukopenia in six patients (21.4%), thrombocytopenia in one patient (3.5%), and mucositis in one patient (3.5%). Median time to progression and overall survival in the patient population were 5.3 (range: 1–43) and 9.8 months (range: 3–73) respectively. Gemcitabine plus metronomic fluoropyrimidines is a well-tolerated and moderately active regimen in heavily pretreated ACC patients.
A R Glover, J T Zhao, J C Ip, J C Lee, B G Robinson, A J Gill, P S H Soon, and S B Sidhu
Adrenocortical carcinoma (ACC) is an aggressive malignancy with high rates of recurrence following surgical resection. Long noncoding RNAs (lncRNAs) play an important role in cancer development. Pathogenesis of adrenal tumours have been characterised by mRNA, microRNA and methylation expression signatures, but it is unknown if this extends to lncRNAs. This study describes lncRNA expression signatures in ACC, adrenal cortical adenoma (ACA) and normal adrenal cortex (NAC) and presents lncRNAs associated with ACC recurrence to identify novel prognostic and therapeutic targets. RNA was extracted from freshly frozen tissue with confirmation of diagnosis by histopathology. Focused lncRNA and mRNA transcriptome analysis was performed using the ArrayStar Human LncRNA V3.0 microarray. Differentially expressed lncRNAs were validated using quantitative reverse transcriptase-PCR and correlated with clinical outcomes. Microarray of 21 samples (ten ACCs, five ACAs and six NACs) showed distinct patterns of lncRNA expression between each group. A total of 956 lncRNAs were differentially expressed between ACC and NAC, including known carcinogenesis-related lncRNAs such as H19, GAS5, MALAT1 and PRINS (P≤0.05); 85 lncRNAs were differentially expressed between ACC and ACA (P≤0.05). Hierarchical clustering and heat mapping showed ACC samples correctly grouped compared with NAC and ACA. Sixty-six differentially expressed lncRNAs were found to be associated with ACC recurrence (P≤0.05), one of which, PRINS, was validated in a group of 20 ACCs and also found to be associated with metastatic disease on presentation. The pathogenesis of adrenal tumours extends to lncRNA dysregulation and low expression of the lncRNA PRINS is associated with ACC recurrence.
Constanze Hantel, Sara Jung, Thomas Mussack, Martin Reincke, and Felix Beuschlein
Owing to high relapse rates and early metastatic spread, prognosis in adrenocortical carcinoma (ACC) patients remains poor, highlighting the importance of developing new treatment alternatives for them. Recently, polychemotherapy regimens including etoposide, doxorubicin, and cisplatin together with mitotane (EDP-M) have been defined as the standard treatment for late-stage disease patients. Nevertheless, the administration of conventional cytostatic drugs is associated with severe and dose-limiting side effects. In an attempt to optimize existing clinical treatment regimens, in this study, we investigated the therapeutic efficacy of EDP-M in comparison with that of a paclitaxel-modified scheme (paclitaxel, doxorubicin, cisplatin plus mitotane (PDP-M)) in preclinical in vitro and in vivo models. In addition, based on an extraordinary uptake phenomenon of liposomes in ACC cells, we further evaluated liposomal variants of these protocols (etoposide, liposomal doxorubicin, liposomal cisplatin plus mitotane (LEDP-M) and nab-paclitaxel, liposomal doxorubicin, liposomal cisplatin plus mitotane (LPDP-M)). In vitro, PDP-M was more potent in the induction of apoptosis and inhibition of cell viability as well as cell proliferation than EDP-M. Following the administration of a single therapeutic cycle, we further demonstrated that LEDP-M and LPDP-M exerted significant antitumoral effects in vivo, which were not as evident upon EDP-M and PDP-M treatments. These results were confirmed in a long-term experiment, in which the highest and sustained antitumoral effects were observed for LEDP-M. In summary, liposomal cytostatic substances could represent a promising option that deserves testing in appropriate clinical protocols for the treatment of ACC patients.
Erwan Thouënnon, Alice Pierre, Yannick Tanguy, Johann Guillemot, Destiny-Love Manecka, Marlène Guérin, L'houcine Ouafik, Mihaela Muresan, Marc Klein, Jérôme Bertherat, Hervé Lefebvre, Pierre-François Plouin, Laurent Yon, and Youssef Anouar
Pheochromocytomas are catecholamine-producing tumors which are generally benign, but which can also present as or develop into malignancy. Molecular pathways of malignant transformation remain poorly understood. Pheochromocytomas express various trophic peptides which may influence tumoral cell behavior. Here, we investigated the expression of trophic amidated peptides, including pituitary adenylate cyclase-activating polypeptide (PACAP), neuropeptide Y (NPY), and adrenomedullin (AM), and their receptors in benign and malignant pheochromocytomas in order to assess their potential role in chromaffin cell tumorigenesis and malignant transformation. PACAP, NPY, and AM are expressed in the majority of pheochromocytomas studied; NPY exhibiting the highest mRNA levels relative to reference genes. Although median gene expression or peptide levels were systematically lower in malignant compared to benign tumors, no statistically significant difference was found. Among all the receptors of these peptides that were analyzed, only the AM receptor RDC1 displayed a differential expression between benign and malignant pheochromocytomas. This receptor exhibited a fourfold higher expression in malignant than in benign tumors. AM and stromal cell-derived factor 1, which has also been described as a ligand for RDC1, increased the number of human pheochromocytoma cells in primary culture and exerted anti-apoptotic activity on rat pheochromocytoma PC12 cells. In addition, RDC1 gene silencing decreased the number of viable PC12 cells. This study shows the expression of several trophic peptides and their receptors in benign and malignant pheochromocytomas, and suggests that AM and its RDC1 receptor could be involved in chromaffin cell tumorigenesis through pro-survival effects. Therefore, AM and RDC1 may represent valuable targets for the treatment of malignant pheochromocytomas.
Sandra Rodríguez-Rodero, Elías Delgado-Álvarez, Agustín F Fernández, Juan L Fernández-Morera, Edelmiro Menéndez-Torre, and Mario F Fraga
Aberrant epigenetics is a hallmark of cancer, and endocrine-related tumors are no exception. Recent research has been identifying an ever-growing number of epigenetic alterations in both genomic DNA methylation and histone post-translational modification in tumors of the endocrine system. Novel microarray and ultra-deep sequencing technologies have allowed the identification of genome-wide epigenetic patterns in some tumor types such as adrenocortical, parathyroid, and breast carcinomas. However, in other cancer types, such as the multiple endocrine neoplasia syndromes and thyroid cancer, tumor information is limited to candidate genes alone. Future research should fill this gap and deepen our understanding of the functional role of these alterations in cancer, as well as defining their possible clinical uses.
O Chabre, R Libé, G Assie, O Barreau, J Bertherat, X Bertagna, J-J Feige, and N Cherradi
Adrenocortical carcinoma (ACC) is a rare cancer with poor prognosis. Local and distant recurrences occur in a subset of tumors classified as ‘aggressive’ ACC (aACC), as opposed to ‘non-aggressive’ ACC (naACC). In this study, we investigated whether tissue and serum microRNAs (miRNAs) are predictive of ACC prognosis. Tissue miRNA expression profiles were determined using microarrays in a test series of six adrenocortical adenomas (ACAs), six naACCs, and six aACCs. Eight miRNAs were selected for further validation by quantitative RT-PCR (ten ACAs, nine naACCs, nine aACCs, and three normal adrenals). Serum levels of five miRNAs were measured in samples from 56 subjects (19 healthy controls (HC), 14 ACA, nine naACC, and 14 aACC patients). MiR-195 and miR-335 levels were significantly decreased in both tumor and serum samples of ACC patients relative to ACA patients or HC. MiR-139-5p and miR-376a levels were significantly increased in aACC compared with naACC patients in tumor samples only. Tissue miR-483-5p was markedly upregulated in a majority of ACC compared with ACA patients or HC, but most importantly, serum miR-483-5p was detected only in aACC patients. High circulating levels of miR-483-5p or low circulating levels of miR-195 were associated with both shorter recurrence-free survival (P=0.0004 and P=0.0014 respectively) and shorter overall survival (P=0.0005 and P=0.0086 respectively). In conclusion, this study reports for the first time that circulating miR-483-5p and miR-195 are promising noninvasive biomarkers with a highly specific prognostic value for the clinical outcome of ACC patients.