miR-211 and MITF modulation by Bcl-2 protein in melanoma cells
MOLECULAR CARCINOGENESIS
Authors: De Luca, Teresa; Pelosi, Andrea; Trisciuoglio, Daniela; D'Aguanno, Simona; Desideri, Marianna; Farini, Valentina; Di Martile, Marta; Bellei, Barbara; Tupone, Maria Grazia; Candiloro, Antonio; Regazzo, Giulia; Rizzo, Maria Giulia; Del Bufalo, Donatella
Abstract
Melanoma, the most lethal form of skin cancer, is frequently associated with alterations in several genes, among which the Bcl-2 oncogene plays an important role in progression, chemosensitivity and angiogenesis. Also microRNA (miRNA) are emerging as modulators of melanoma development and progression, and among them, miR-211, located within the melastatin-1/TRPM1 (transient receptor potential cation channel, subfamily M, member 1 protein) gene, is prevalently expressed in the melanocyte lineage and acts as oncosuppressor. Using several human melanoma cell lines and their Bcl-2 stably overexpressing derivatives, we evaluated whether there was a correlation between expression of Bcl-2 and miR-211. Western blot analysis and quantitative real-time polymerase chain reaction demonstrated reduced expression of pri-miR-211, miR-211, TRPM1, and MLANA levels, after Bcl-2 overexpression, associated with increased expression of well-known miR-211 target genes. Overexpression of mature miR-211 in Bcl-2 overexpressing cells rescued Bcl-2 ability to increase cell migration. A decreased nuclear localization of microphthalmia-associated transcription factor (MITF), a co-regulator of both miR-211 and TRPM1, and a reduced MITF recruitment at the TRPM1 and MLANA promoters were also evidenced in Bcl-2 overexpressing cells by immunofluorescence and chromatin immunoprecipitation experiments, respectively. Reduction of Bcl-2 expression by small interference RNA confirmed the ability of Bcl-2 to modulate miR-211 and TRPM1 expression. (c) 2015 Wiley Periodicals, Inc.
High expression of MLANA in the plasma of patients with head and neck squamous cell carcinoma as a predictor of tumor progression
HEAD AND NECK-JOURNAL FOR THE SCIENCES AND SPECIALTIES OF THE HEAD AND NECK
Authors: Rodrigues-Junior, Dorival Mendes; Tan, Soon Sim; Lim, Sai Kiang; Viana, Luciano de Souza; Carvalho, Andre Lopes; Vettore, Andre Luiz; Iyer, N. Gopalakrishna
Abstract
Background There is a paucity of plasma-based biomarkers that predict outcome in patients with head and neck squamous cell carcinoma (HNSCC) treated with chemoradiation therapy (CRT). Here, we evaluate the prognostic potential of plasma Melanoma-Antigen Recognized by T-cells 1 (MLANA) in this setting. Methods MLANA expression in HNSCC lines were evaluated by reverse transcription polymerase chain reaction, whereas plasma levels were quantified using ELISA in 48 patients with locally advanced HNSCC undergoing a phase 2 trial with CRT. Results MLANA is expressed at variable levels in a panel of HNSCC lines. In plasma, levels were elevated in patients with tumor relapse compared to those without (P < .004); 73.9% of the patients expressing high plasma MLANA levels progressed with recurrent disease (P = .020). Multivariate analysis showed that plasma MLANA levels and tumor resectability were independent prognostic factors for progression free survival. Conclusion Plasma MLANA expression appears to be an effective noninvasive biomarker for outcomes in patients treated with CRT, and could potentially guide therapeutic decisions in this context.