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Pennati M, Lopergolo A, Profumo V, De Cesare M, Sbarra S, Valdagni R, Zaffaroni N, Gandellini P, Folini M. miR-205 impairs the autophagic flux and enhances cisplatin cytotoxicity in castration-resistant prostate cancer cells. Biochem Pharmacol 2013; 87:579-97. [PMID: 24370341 DOI: 10.1016/j.bcp.2013.12.009] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 12/10/2013] [Accepted: 12/11/2013] [Indexed: 12/11/2022]
Abstract
Compelling evidence suggests that epithelial-to-mesenchymal transition is involved in the resistance of human cancer cells to chemotherapy. We previously reported that the expression of miR-205, a miRNA down-regulated in prostate cancer, is further repressed in prostate cancer cells undergoing epithelial-to-mesenchymal transition, suggesting a possible involvement of the miRNA in the acquisition of the chemoresistant phenotype. In the present study, we show that miR-205 replacement in castration-resistant mesenchymal prostate cancer cells caused an enhancement of cisplatin cytotoxic activity in vitro and in vivo, as a consequence of autophagy impairment. Specifically, the constraints on the autophagic flux were associated to the miRNA-dependent down-regulation of the lysosome-associated proteins RAB27A and LAMP3. These findings suggest that miR-205-mediated impairment of the autophagic pathway may interfere with the detoxifying capabilities of prostate cancer cells in their attempt to cope with cisplatin-induced detrimental effects. Overall, our data indicate that (i) loss of miR-205 may indeed contribute to acquire mesenchymal tracts and concomitantly establish a permissive autophagic milieu that confers a chemotherapy resistant phenotype to prostate cancer cells, and (ii) strategies aimed at restoring miR-205 expression levels may represent a successful approach to overcome resistance of prostate cancer to platinum compounds.
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Affiliation(s)
- Marzia Pennati
- Molecular Pharmacology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, via G. Amadeo 42, 20133 Milano, Italy
| | - Alessia Lopergolo
- Molecular Pharmacology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, via G. Amadeo 42, 20133 Milano, Italy
| | - Valentina Profumo
- Molecular Pharmacology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, via G. Amadeo 42, 20133 Milano, Italy
| | - Michelandrea De Cesare
- Molecular Pharmacology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, via G. Amadeo 42, 20133 Milano, Italy
| | - Stefania Sbarra
- Molecular Pharmacology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, via G. Amadeo 42, 20133 Milano, Italy
| | - Riccardo Valdagni
- Department of Radiation Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, via G. Venezian 1, 20133 Milano, Italy; Prostate Cancer Program, Fondazione IRCCS Istituto Nazionale dei Tumori, via G. Venezian 1, 20133 Milano, Italy
| | - Nadia Zaffaroni
- Molecular Pharmacology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, via G. Amadeo 42, 20133 Milano, Italy.
| | - Paolo Gandellini
- Molecular Pharmacology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, via G. Amadeo 42, 20133 Milano, Italy
| | - Marco Folini
- Molecular Pharmacology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, via G. Amadeo 42, 20133 Milano, Italy
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Abstract
The promise of targeting epigenetic abnormalities for cancer therapy has not been realized for solid tumours, although increasing evidence is demonstrating its worth in haematological malignancies. In fact, true clinical efficacy in haematopoietic-related neoplasms has only become evident at low doses of epigenetic-targeting drugs (namely, inhibitors of histone deacetylase and DNA methyltransferases). Describing data from preclinical studies and early clinical trial results, we hypothesize that in using low-dose epigenetic-modulating agents, tumour cells can be reprogrammed, which overrides any immediate cytotoxic and off-target effect observed at high dose. We suggest that such optimization of drug dosing and scheduling of currently available agents could give these agents a prominent place in cancer management--when used alone or in combination with other therapies. If so, optimal use of these known agents might also pave the way for the introduction of other agents that target the epigenome.
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