miR-205 enhances radiation sensitivity of prostate cancer cells by impairing DNA damage repair through PKCε and ZEB1 inhibition
Autor: | Monica Tortoreto, Valentina Doldi, Riccardo Valdagni, Marco Folini, Paolo Gandellini, Nadia Zaffaroni, C. Stucchi, Rihan El Bezawy, Stella Tinelli, Tiziana Rancati, Valentina Zuco |
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Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
Male
0301 basic medicine Cancer Research DNA Repair Context (language use) Mice SCID Protein Kinase C-epsilon Transfection Radiation Tolerance lcsh:RC254-282 Radiosensitivity Mice 03 medical and health sciences 0302 clinical medicine Radiation sensitivity DU145 RNA interference Cell Line Tumor Radioresistance Animals Humans Clonogenic assay PKCε Chemistry Research Prostate Cancer Molecular Mimicry Prostatic Neoplasms Zinc Finger E-box-Binding Homeobox 1 miR-205 lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens Xenograft Model Antitumor Assays Comet assay MicroRNAs 030104 developmental biology Oncology 030220 oncology & carcinogenesis PC-3 Cells Cancer research Signal transduction |
Zdroj: | Journal of Experimental & Clinical Cancer Research, Vol 38, Iss 1, Pp 1-11 (2019) Journal of Experimental & Clinical Cancer Research : CR |
ISSN: | 1756-9966 |
Popis: | Background Radiotherapy is one of the main treatment options for non-metastatic prostate cancer (PCa). Although treatment technical optimization has greatly improved local tumor control, a considerable fraction of patients still experience relapse due to the development of resistance. Radioresistance is a complex and still poorly understood phenomenon involving the deregulation of a variety of signaling pathways as a consequence of several genetic and epigenetic abnormalities. In this context, cumulative evidence supports a functional role of microRNAs in affecting radioresistance, suggesting the modulation of their expression as a novel radiosensitizing approach. Here, we investigated for the first time the ability of miR-205 to enhance the radiation response of PCa models. Methods miR-205 reconstitution by a miRNA mimic in PCa cell lines (DU145 and PC-3) was used to elucidate miR-205 biological role. Radiation response in miRNA-reconstituted and control cells was assessed by clonogenic assay, immunofluorescence-based detection of nuclear γ-H2AX foci and comet assay. RNAi was used to silence the miRNA targets PKCε or ZEB1. In addition, target-protection experiments were carried out using a custom oligonucleotide designed to physically disrupt the pairing between the miR-205 and PKCε. For in vivo experiments, xenografts generated in SCID mice by implanting DU145 cells stably expressing miR-205 were exposed to 5-Gy single dose irradiation using an image-guided animal micro-irradiator. Results miR-205 reconstitution was able to significantly enhance the radiation response of prostate cancer cell lines and xenografts through the impairment of radiation-induced DNA damage repair, as a consequence of PKCε and ZEB1 inhibition. Indeed, phenocopy experiments based on knock-down of either PKCε or ZEB1 reproduced miR-205 radiosensitizing effect, hence confirming a functional role of both targets in the process. At the molecular level, miR-205-induced suppression of PKCε counteracted radioresistance through the impairment of EGFR nuclear translocation and the consequent DNA-PK activation. Consistently, disruption of miR-205-PKCε 3’UTR pairing almost completely abrogated the radiosensitizing effect. Conclusions Our results uncovered the molecular and cellular mechanisms underlying the radiosensitizing effect of miR-205. These findings support the clinical interest in developing a novel therapeutic approach based on miR-205 reconstitution to increase PCa response to radiotherapy. |
Databáze: | OpenAIRE |
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