The imaging dyes acridine orange and LysoTracker Red were obtained from Invitrogen (Carlsbad, CA), FITC mouse anti-human CD107a (LAMP1) and CD107b (LAMP2) antibodies from BD Biosciences (Franklin Lakes, NJ), peptidase inhibitors CA-074-Me and pepstatin A, and fluorogenic peptidase substrate Z-RR-AMC from Enzo Life Sciences (Plymouth Meeting, PA), caspase-3 inhibitor Z-DEVD-FMK from R&D Systems (Minneapolis, MN); caspase-3 substrate Ac-DEVD-AMC from Bachem Biosciences,
Inc (King of Prussia, PA); All other reagents were obtained from Sigma-Alrich (St. Louis, MO) unless otherwise stated. Compounds were dissolved in DMSO with final concentrations less than 0.3 %. In vivo tumor treatment Athymic nude mice from Harlan Bioproducts, Inc. were inoculated subcutaneously with 1×106 A-1210477 Bxpc3 cells in the right flank. Tumor sizes were monitored with calipers and when tumors reached an average of 5 mm in diameter, mice were randomized and treated daily with equimolar doses of sigma-2 receptor ligands SV119 (1.0 mg), SW43 (1.1 mg), PB28 (0.9 mg), or PB282 (0.9 mg) resuspended in vehicle consisting of 5 % DMSO, 5 % EtOH, and 10 % Cremophor in 1X PBS and injected intraperitoneally. Data represents mean ± SEM, n = 7–10 per group. Confocal microscopy Cells grown on glass cover slips were incubated with SW120 or PB385 (100 nM) in the presence of LysoTracker Red (25 nM) for 30 minutes at 37°C. Cells were washed with PBS and fixed in 2 % paraformaldehyde for 30 minutes
at 37°C prior to additional washing and mounting with ProLong Gold antifade reagent. Confocal imaging was performed on a Carl Zeiss VX-689 Axiovert 100 inverted microscope, fitted with LSM 510 laser scanning microscope camera and software. Images were collected with filter bandwidths corresponding to 505–530 nm for green, 560–615 nm for red, and > 650 nm for far red, with 4 scans over 11.8 seconds. Fluorescence microscopy Cells grown on glass cover slips
were loaded with acridine orange (2 μg/mL) for 15 minutes at 37°C prior to treatment Dynein for one hour with compounds. Cover slips were inverted onto slides and images taken immediately at 40X magnification on anOlympus BX51 microscope fitted with a U-LH100HE reflective fluorescence system and equipped with a Diagnositic Instruments, Inc. SPOT camera and software. Chroma Technology Corp filter sets were used for green (exciter: D480/30x, emitter: 535/40 m, beamsplitter: 505dclp), red (exciter: D540/25x, emitter: 606/55 m, beamsplitter: 556dclp), and blue (exciter: D360/40x, emitter: 460/50 m, beamsplitter: 400dclp). Scale bar equals 20 μm. Dye AZD1390 cell line retention analysis by flow cytometry Cells were incubated with acridine orange (2 μg/mL) or LysoTracker Green (25 nM) for 30 minutes at 37°C prior to treatment with compounds for one hour. Cells were washed and mean fluorescence quantified with a FACSCalibur flow cytometer (BD Biosciences, San Jose, CA). Mean fluorescence was normalized to DMSO to determine the degree of lysosomal permeabilization.