Fig. 3

Depletion of HSF1 induces spindle abnormalities. a Depletion efficiency of HSF1. CGL2 cells were transduced with virions containing no shRNA (pLKO.1) or HSF1-specific shRNA (sh-HSF1). Beginning at 50 h post-transduction, the cells were collected daily for analysis of HSF1 depletion efficiency by immunoblotting. Red arrowheads indicate the positions of HSF1 bands. b Representative images of CGL2 cells 52 h after transduction with virions containing no shRNA (pLKO.1) or HSF1-specific shRNA (sh-HSF1). Mitotic indices (MIs) were determined by counting DAPI-stained interphase and mitotic cells at 40× magnification using a fluorescence microscope. At least 1000 cells were counted. Data presented are the mean ± SD from three independent experiments. c HSF1 depletion induced spindle abnormalities. Cells were transduced as described in b and then subjected to mitotic spindle analysis by immunofluorescence staining. Representative images show mitotic spindles from CGL2 cells transduced with virions containing pLKO.1 control or HSF1 shRNA. The results (mean ± SD) were determined from at least 300 mitotic cells from three independent experiments. *p < 0.01 by Student’s t-test as compared with cells transduced with pLKO.1 control virion