Expression of Dicer and Drosha in triple-negative breast cancer
- Nadia Passon,
- Anna Gerometta,
- Cinzia Puppin,
- Elisa Lavarone,
- Fabio Puglisi,
- Gianluca Tell,
- Carla Di Loreto,
- Giuseppe Damante
- Correspondence to Giuseppe Damante, Dipartimento di Scienze Mediche e Biologiche, Piazzale Kolbe 4, 33100 Udine, Italy;
Contributors NP: Quantitative reverse transcription PCR; AG: RNA extraction and immunohyistochemistry; CP: quantitative reverse transcription PCR; EL: immunohistochemistry and western blot; FP: statistics, writing the manuscript; GT: cell line experiments; CDL: selection of cancer specimens, immunohistochemistry; GD: ideation of the project and writing the manuscript.
- Accepted 13 December 2011
- Published Online First 18 January 2012
Aims Dicer and Drosha are components of the miRNA-producing machinery and their altered expression may play a role in cancer progression. The main purpose of this study was a detailed investigation of Dicer and Drosha expression and localisation in triple-negative breast cancers.
Methods Thirty-one triple-negative breast cancers and several breast cancer cell lines were investigated. Expression of Dicer and Drosha was evaluated at the mRNA level by quantitative reverse transcription PCR and at the protein level by immunohistochemistry or western blot.
Results Compared with normal breast tissues, a wide variation of Dicer and Drosha mRNA levels was detected in triple-negative breast cancers. As a group, Drosha mRNA levels in triple-negative breast cancers were significantly higher than those in normal breast tissues. Immunohistochemical data confirmed higher expression of Drosha protein in triple-negative breast cancers. In normal breast tissues Dicer was detectable predominantly in the cytoplasm of basal/myoepithelial cells only. In contrast, in the majority of triple-negative breast cancers, intense Dicer staining was detectable also in the nuclear compartment. Detection of Dicer and Drosha mRNA and protein levels in breast cancer cell lines confirmed the nuclear localisation of Dicer, suggesting, in addition, that the steady-state protein levels could be controlled by post-mRNA regulatory events.
Conclusions These findings indicate that Dicer and Drosha expression is deregulated in triple-negative breast cancers.
- Breast cancer
- cancer genetics
- molecular genetics
- thyroid cancer
- tumour cell culture
Funding This work is funded by a grant from Associazione Italiana per la Ricerca sul Cancro (AIRC) to GD (project no IG 10296).
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.