Abstract | BACKGROUND:
Chloride channels are physiologically involved in cell division and motility. Chloride intracellular channel 1 (CLIC1) is overexpressed in a variety of human solid tumors compared with normal tissues, suggesting a potential involvement of CLIC1 in the regulation of tumorigenesis. This led us to investigate the role of CLIC1 in gliomagenesis. METHODS: We used the neurosphere system to isolate stem/progenitor cells from human glioblastomas (GBMs). CLIC1 targeting in GBM neurospheres was achieved by both lentiviral-mediated short-hairpin RNA transduction and CLIC1 antibody treatment, and its effect on stem-like properties was analyzed in vitro by proliferation and clonogenic assays and in vivo by orthotopic injection in immunocompromised mice. Channel activity was studied by perforated patch clamp technique. Differences in expression were analyzed by analysis of variance with Tamhane's multiple comparison test. Kaplan-Meier analyses and log-rank test were used to assess survival. All statistical tests were two-sided. RESULTS: CLIC1 was statistically significantly overexpressed in GBMs compared with normal brain tissues (P < .001) with a better survival of patients with CLIC1 low-expressing tumors (CLIC1(low) vs CLIC1(high) survival: χ(2) = 74.35; degrees of freedom = 1; log-rank P < .001). CLIC1 was variably expressed in patient-derived GBM neurospheres and was found enriched in the stem/progenitor compartment. CLIC1 silencing reduced proliferative (P < .01), clonogenic (P < .01), and tumorigenic capacity (P < .05) of stem/progenitor cells. The reduction of CLIC1 chloride currents with a specific CLIC1 antibody mirrored the biological effects of CLIC1 silencing in GBM patient-derived neurospheres. CONCLUSIONS: Reduced gliomagenesis after CLIC1 targeting in tumoral stem/progenitor cells and the finding that CLIC1 expression is inversely associated with patient survival suggest CLIC1 as a potential target and prognostic biomarker.
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Authors | Matteo Setti, Nicoletta Savalli, Daniela Osti, Cristina Richichi, Marina Angelini, Paola Brescia, Lorenzo Fornasari, Maria Stella Carro, Michele Mazzanti, Giuliana Pelicci |
Journal | Journal of the National Cancer Institute
(J Natl Cancer Inst)
Vol. 105
Issue 21
Pg. 1644-55
(Nov 06 2013)
ISSN: 1460-2105 [Electronic] United States |
PMID | 24115360
(Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- CLIC1 protein, human
- Chloride Channels
- RNA, Small Interfering
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Topics |
- Analysis of Variance
- Animals
- Blotting, Western
- Brain Neoplasms
(metabolism, pathology)
- Carcinogenesis
(metabolism)
- Chloride Channels
(metabolism)
- Fluorescent Antibody Technique
- Gene Expression Regulation, Neoplastic
- Glioblastoma
(metabolism, pathology)
- Humans
- Immunohistochemistry
- Kaplan-Meier Estimate
- Mice
- Neoplastic Stem Cells
(metabolism)
- RNA, Small Interfering
(pharmacology)
- Tumor Stem Cell Assay
- Up-Regulation
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