Ely stained cells from six 406 fields per tumor slide. Senescence-associated b-galactosidase (SA-b-Gal) was used as a biomarker for cellular senescence [33]. For b-galactosidase staining, frozen tissues were sectioned at 8 mm thick and fixed and stained with staining solution mix containing X-gal at PH 6.0, and then the slides were rinsed with distilled water, dehydrated through alcohol, cleared in Xylene and mounted with paramount. SA-b-galactosidase data were calculated as the average percentage of positively stained cells from six fields that each contained at least 100 cells. To assess tumor vascularity, cluster of differentiation 31 (CD31) staining was performed [34?6]. For each tumor, one 5 mm tissue section was cut and deparaffinised in xylene, rehydrated in a graded series of ethanol solutions, and heated in a microwave oven in 0.01 M sodium citrate buffer (pH 6.0) for 23727046 10 minutes for antigen retrieval. Specimens were blocked in 10 percent normal goat serum (Sigma-Aldrich) for 20 min. The sections were then incubated with a 1:50 diluted mouse CD31 monoclonal antibody (Santa Cruz Biotechnology, Santa Cruz CA), at room temperature for 1 h, and then incubated with FITC labelled goat anti-rabbit antibody (Santa Cruz Biotechnology). Negative controls were produced by eliminating the primary antibodies from the diluents. After washing in PBS with 0.05 Tween20, the slides were counter-stained with DAPI (Sigma-Aldrich). Six fields at 2006 magnification per section, randomly selected from non-necrotic regions of each tumors were examined with a fluorescent microscope (Zeiss Axiovert 200 m, Carl Zeiss Microscopy, Peabody MA). All blood vessels positive for CD31 and with distinct (slot-like, ITI 007 site tubular, or polymorphous) lumens were counted. Microvessel density (MVD) was expressed as number of positive lumens for per field.Immunohistochemistry of the tumors. Cell apoptosis and senescence assays following radiation in vitro. MDA-MB-231 cells were harvested by standardtrypsinization, washed with PBS and re-suspended in complete medium. The cells were seeded at 0.36106 cell/5 ml medium/ plate (60 mm), grown overnight and then irradiated with 16 Gy (same system as used to treat the tumors). The cells were placed back into the incubator immediately after irradiation. For apoptosis detection, cells (96 hrs post radiation treatment, n = 5; and untreated cells, n = 4) were gently trypsinized and washed once in PBS and 0.16106 cells were stained with Methionine enkephalin biological activity Annexin 5 and PI using the FITC Annexin5 apoptosis detection kit (BD Biosciences) according to manufacturer’s direction, followed by flow cytometry [37]. SA-b-Gal expression was measured using a standard senescence detection kit (BD Biosciences) according to the manufacturer’s instructions. In brief, culture media were removed and the cells were then washed once with PBS and fixed with the fixation solution for 15 min at room temperature. After two additional washes with PBS, the staining solution containing 1 mg/ml 5bromo-4-chloro-3-indolyl-b-d-galactoside was added to each well. Cells (n = 4 for both control and treated cells) were incubated at 37uC overnight and then observed under a microscope for development of blue color. The percentage of blue stained cells versus total cells was measured by choosing 6 random microscopic fields that had at least 100 cells for each dataset.To estimate change in cell size post treatment, trypsinized cells were loaded into a hemocytometer and images at 2006 amplificati.Ely stained cells from six 406 fields per tumor slide. Senescence-associated b-galactosidase (SA-b-Gal) was used as a biomarker for cellular senescence [33]. For b-galactosidase staining, frozen tissues were sectioned at 8 mm thick and fixed and stained with staining solution mix containing X-gal at PH 6.0, and then the slides were rinsed with distilled water, dehydrated through alcohol, cleared in Xylene and mounted with paramount. SA-b-galactosidase data were calculated as the average percentage of positively stained cells from six fields that each contained at least 100 cells. To assess tumor vascularity, cluster of differentiation 31 (CD31) staining was performed [34?6]. For each tumor, one 5 mm tissue section was cut and deparaffinised in xylene, rehydrated in a graded series of ethanol solutions, and heated in a microwave oven in 0.01 M sodium citrate buffer (pH 6.0) for 23727046 10 minutes for antigen retrieval. Specimens were blocked in 10 percent normal goat serum (Sigma-Aldrich) for 20 min. The sections were then incubated with a 1:50 diluted mouse CD31 monoclonal antibody (Santa Cruz Biotechnology, Santa Cruz CA), at room temperature for 1 h, and then incubated with FITC labelled goat anti-rabbit antibody (Santa Cruz Biotechnology). Negative controls were produced by eliminating the primary antibodies from the diluents. After washing in PBS with 0.05 Tween20, the slides were counter-stained with DAPI (Sigma-Aldrich). Six fields at 2006 magnification per section, randomly selected from non-necrotic regions of each tumors were examined with a fluorescent microscope (Zeiss Axiovert 200 m, Carl Zeiss Microscopy, Peabody MA). All blood vessels positive for CD31 and with distinct (slot-like, tubular, or polymorphous) lumens were counted. Microvessel density (MVD) was expressed as number of positive lumens for per field.Immunohistochemistry of the tumors. Cell apoptosis and senescence assays following radiation in vitro. MDA-MB-231 cells were harvested by standardtrypsinization, washed with PBS and re-suspended in complete medium. The cells were seeded at 0.36106 cell/5 ml medium/ plate (60 mm), grown overnight and then irradiated with 16 Gy (same system as used to treat the tumors). The cells were placed back into the incubator immediately after irradiation. For apoptosis detection, cells (96 hrs post radiation treatment, n = 5; and untreated cells, n = 4) were gently trypsinized and washed once in PBS and 0.16106 cells were stained with Annexin 5 and PI using the FITC Annexin5 apoptosis detection kit (BD Biosciences) according to manufacturer’s direction, followed by flow cytometry [37]. SA-b-Gal expression was measured using a standard senescence detection kit (BD Biosciences) according to the manufacturer’s instructions. In brief, culture media were removed and the cells were then washed once with PBS and fixed with the fixation solution for 15 min at room temperature. After two additional washes with PBS, the staining solution containing 1 mg/ml 5bromo-4-chloro-3-indolyl-b-d-galactoside was added to each well. Cells (n = 4 for both control and treated cells) were incubated at 37uC overnight and then observed under a microscope for development of blue color. The percentage of blue stained cells versus total cells was measured by choosing 6 random microscopic fields that had at least 100 cells for each dataset.To estimate change in cell size post treatment, trypsinized cells were loaded into a hemocytometer and images at 2006 amplificati.
