Suppression of REV7 enhances cisplatin sensitivity in ovarian clear cell carcinoma cells.
Bottom Line: Enhanced immunoreactivity to REV7 was associated with poor prognosis represented by reduced progression-free survival in advanced stage (stage II-IV) EOC as assessed using Kaplan-Meier curves and log-rank tests.Knockdown of REV7 in CCC cells decreased cell proliferation without affecting cell cycle distribution.In a nude mouse tumor xenograft model, inoculated REV7-knockdown tumors showed significantly reduced tumor volumes after cisplatin treatment compared with those of the control group.
Affiliation: Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Japan; Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Nagoya, Japan.Show MeSH
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Mentions: As CDDP induces DNA damage of intrastrand and interstrand cross-links, which are repaired by nucleotide excision repair and homologous recombination repair machineries, it is possible that REV7 depletion causes dysfunction of DNA repair machinery and accumulation of DNA damage in cells, causing enhancement of apoptosis. DNA damage of double-strand breaks was assessed in shREV7 and shCont cells by immunofluorescence staining using anti-phospho-H2AX antibody. TOV-21G-derived shREV7 and shCont cells were treated with 50 μM CDDP for 24 h, and the cells were fluorescently immunostained for phospho-H2AX. Positive immunoreactivity, showing small foci formation in the nuclei, increased after treatment at a significantly high frequency in REV7-depleted cells compared with that of control cells (Fig.4). As a comparison, the cells treated with UV irradiation at 20 J/m2 were immunostained with anti-phospho-H2AX antibody 12 h after UV irradiation. Positive immunoreactivity was also detected in REV7-depleted cells at a significantly high frequency (Fig.4). These findings indicate that REV7 depletion results in accumulation of double-strand breaks in response to CDDP treatment.
Affiliation: Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Japan; Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Nagoya, Japan.