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ABSTRACT: Purpose
To identify tissue microRNAs predictive of sunitinib activity in patients with metastatic renal-cell-carcinoma (MRCC) and to evaluate in vitro their mechanism of action in sunitinib resistance.Methods
We screened 673 microRNAs using TaqMan Low-density-Arrays (TLDAs) in tumors from MRCC patients with extreme phenotypes of marked efficacy and resistance to sunitinib, selected from an identification cohort (n = 41). The most relevant differentially expressed microRNAs were selected using bioinformatics-based target prediction analysis and quantified by qRT-PCR in tumors from patients presenting similar phenotypes selected from an independent cohort (n = 101). In vitro experiments were conducted to study the role of miR-942 in sunitinib resistance.Results
TLDAs identified 64 microRNAs differentially expressed in the identification cohort. Seven candidates were quantified by qRT-PCR in the independent series. MiR-942 was the most accurate predictor of sunitinib efficacy (p = 0.0074). High expression of miR-942, miR-628-5p, miR-133a, and miR-484 was significantly associated with decreased time to progression and overall survival. These microRNAs were also overexpressed in the sunitinib resistant cell line Caki-2 in comparison with the sensitive cell line. MiR-942 overexpression in Caki-2 up-regulates MMP-9 and VEGF secretion which, in turn, promote HBMEC endothelial migration and sunitinib resistance.Conclusions
We identified differentially expressed microRNAs in MRCC patients presenting marked sensitivity or resistance to sunitinib. MiR-942 was the best predictor of efficacy. We describe a novel paracrine mechanism through which high miR-942 levels in MRCC cells up-regulates MMP-9 and VEGF secretion to enhance endothelial migration and sunitinib resistance. Our results support further validation of these miRNA in clinical confirmatory studies.
SUBMITTER: Prior C
PROVIDER: S-EPMC3901669 | biostudies-literature | 2014
REPOSITORIES: biostudies-literature

Prior Celia C Perez-Gracia Jose Luis JL Garcia-Donas Jesus J Rodriguez-Antona Cristina C Guruceaga Elizabeth E Esteban Emilio E Suarez Cristina C Castellano Daniel D del Alba Aránzazu González AG Lozano Maria Dolores MD Carles Joan J Climent Miguel Angel MA Arranz Jose Angel JA Gallardo Enrique E Puente Javier J Bellmunt Joaquim J Gurpide Alfonso A Lopez-Picazo Jose Maria JM Hernandez Alvaro Gonzalez AG Mellado Begoña B Martínez Esther E Moreno Fernando F Font Albert A Calvo Alfonso A
PloS one 20140124 1
<h4>Purpose</h4>To identify tissue microRNAs predictive of sunitinib activity in patients with metastatic renal-cell-carcinoma (MRCC) and to evaluate in vitro their mechanism of action in sunitinib resistance.<h4>Methods</h4>We screened 673 microRNAs using TaqMan Low-density-Arrays (TLDAs) in tumors from MRCC patients with extreme phenotypes of marked efficacy and resistance to sunitinib, selected from an identification cohort (n = 41). The most relevant differentially expressed microRNAs were s ...[more]