Oral Presentation 5th International Symposium on Phaeochromocytoma and Paraganglioma 2017

miR-21-3p and miR-183-5p: novel risk markers for metastatic pheochromocytoma and paraganglioma (#26)

Bruna Calsina 1 , Luís Castro-Vega 2 , Lucia Inglada-Perez 1 , Rafael Torres- Pérez 1 , Maria Currás-Freixes 1 , Rocío Letón 1 , Cristina Montero-Conde 1 , Laura Remacha Medina 1 , Giuseppe Opocher 3 , Henri Timmers 4 , Felix Beuschlein 5 , Ronald Dekrijger 6 , Graeme Eisenhofer 7 , Massimo Mannelli 8 , Cristina Rodríguez-Antona 1 , Alberto Cascon Soriano 1 , Anne-Paule Gimenez-Roqueplo 2 , mercedes Robledo 1
  1. Hereditary Endocrine Cancer Group, Human Cancer Genetics Programme, CNIO, Madrid, Spain
  2. INSERM, Paris-Cardiovascular Research Center, Paris, France
  3. Department of Endocrinology, Department of Medical and Surgical Sciences, University of Padova, Padova, Italy
  4. Department of Internal Medicine, Radboud University Medical Centre, Nijmegen, Netherlands
  5. Department of Endocrinology, University Hospital München, Munich, Germany
  6. Department of Pathology, Reinier de Graaf Hospital, Delft, Netherlands
  7. Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
  8. Department of Experimental and Clinical Biomedical Sciences Mario Serio, University of Florence and Istituto Toscano Tumori, Florence, Italy

There is a lack of molecular markers for predicting metastases in PPGL patients, which could improve their clinical management. OMIC platforms have demonstrated to be a robust tool for identifying prognostic markers.

In this study, we used the miRNA profiling of 443 tumor samples and identified > 50 miRNA differentially expressed between benign and metastatic PPGLs. After applying strict filtering criteria, eight miRNAs were selected for validation using a well characterized independent series (n=49). Six miRNAs were validated: five upregulated (miR-21-3p, miR-182-5p, miR-96-5p, miR-551b-3p and miR-183-5p), and one downregulated (miR-202-5p).

After assessing these six validated miRNA as prognostic markers, miR-21-3p and miR-183-5p were significantly associated with a shorter time to progression. Furthermore, a stepwise logistic regression model selected these two miRNAs in combination with SDHB genotype as the best classifier of malignancy. Thus, we define miR-21-3p and miR-183-5p as potential novel metastatic PPGL markers.

Six remarkable proteins potentially implicated in malignant behavior of the disease were indicated from integration of the miRNA profiles and the transcriptome of these miRNA targets (Targetome) predicted in silico. These particular proteins highlighted the promising importance of mTOR pathway in the progression of the disease. Validation of those targets in the same independent series is being performed.

Furthermore, we have generated eight stable neuroblastoma cell lines to elucidate the phenotypic and functional implication in metastases of these miRNAs. Preliminary results show that overexpression of miR-21-3p promotes proliferation in SDHB-deficient and WT cell lines. We will use this model to further evaluate their implication in invasion and migration, study the validated targets in vitro, and we aim to identify promising metastasic specific weaknesses and strategies for the treatment of metastatic PPGL patients.