Or serum pools (n = 25 for each pool) for TLDA profiling. Total RNA was isolated from serum samples collected at the University of Michigan using the miRNeasy RNA isolation kit (Qiagen) as follows: 400 ml serum was divided into four, 100 ml aliquots. Each aliquot was denatured using 10X volume (1 ml) Qiazol, which was vortexed and incubated at room Platelet clusters might be also found not only within blood vessels temperature for 10 min. C. elegans spiked-in oligonucleotides were introduced (as a mixture of 25 fmol of each oligonucleotide in 5 ml total volume per liquid sample) after denaturation, which were used for normalization of variability in RNA isolation across samples as previously described [1]. RNA 15481974 was extracted using 0.2X volume chloroform (220 ml), and total RNA was isolated following the manufacturer’s protocol. For a given sample, RNA isolated from each 100 ml aliquot was pooled and concentrated to 100 ml volume over Microcon YM-3 filter units (Millipore) at 14,0006g, 1.5 hour, 4uC, which were loaded inverted into pre-weighed 1.5 ml microcentrifuge tubes and eluted at 10006g, 3 min, 4uC. Tubes plus eluate was weighed on an analytical scale and brought to 100 ml with Elution Buffer. RNA was stored at 280uC.Materials and Methods Cell CultureLNCaP (ATCCH CRL-1740TM) and VCaP [10] human prostate cancer cell lines were cultured in RPMI 1640 and DMEM, respectively, each supplemented with 10 FBS (or under serum-free conditions, as noted), at 37uC in a 5 CO2 incubator. Hypoxic conditions (1 O2) were established in a Thermo Scientific 3595 Incubator (ThermoFisher), with cells maintained under normoxic conditions (20 O2) in parallel.Collection and Processing of Clinical Tissue SectionsLaser-capture micro-dissection (LCM) of frozen-tissue sections. 1315463 Sections of flash-frozen prostate and lymph nodeRNA Isolation from Cultured Cells and Conditioned MediaConditioned media was Title Loaded From File removed from cells cultured for 24, 48 or 72 hours under normoxic or hypoxic conditions. Cells were washed with 5 ml PBS and lysed on ice directly in the culture dish with 600 ml Lysis/Binding buffer from the mirVana miRNA isolation kit (Ambion). Lysates were harvested manually with a sterile cell scraper and transferred to an RNase2/DNase-free 2 ml microcentrifuge tube. RNA was extracted from cell lysates following the manufacturer’s recommended protocol for total RNA isolation. Cellular debris was removed from a 500 ml aliquot of conditioned media (10 ml total volume) by filtration through a 0.2 mm NanoSep filtration unit (Millipore) at 14,0006g, 5 min, at room temperature. 400 ml filtered sample was combined with 400 ml 2X Denaturing Solution (Ambion) and vortexed. C. elegans spiked-in oligonucleotides were introduced (as a mixture of 25 fmol of each oligonucleotide in 5 ml total volume per liquid sample) after denaturation and used for normalization of variability in RNA isolation across samples as previously described [1]. RNA was extracted from conditioned media lysates using the mirVana PARIS kit (Ambion) following the manufacturer’s recommended protocol for total RNA isolation.Ethics StatementAll clinical samples were obtained from subjects who provided written informed consent. Studies were performed in accordanceobtained from radical prostatectomy and rapid autopsy, respectively, were assessed by a pathologist to define regions of tumor epithelial cells. For laser capture microdissection 5 mm sections of frozen tissue were made on a LeicaTMCM3050S cryostat at 220uC (Leica, Wetzlar, Germany), placed onto PEN Membrane F.Or serum pools (n = 25 for each pool) for TLDA profiling. Total RNA was isolated from serum samples collected at the University of Michigan using the miRNeasy RNA isolation kit (Qiagen) as follows: 400 ml serum was divided into four, 100 ml aliquots. Each aliquot was denatured using 10X volume (1 ml) Qiazol, which was vortexed and incubated at room temperature for 10 min. C. elegans spiked-in oligonucleotides were introduced (as a mixture of 25 fmol of each oligonucleotide in 5 ml total volume per liquid sample) after denaturation, which were used for normalization of variability in RNA isolation across samples as previously described [1]. RNA 15481974 was extracted using 0.2X volume chloroform (220 ml), and total RNA was isolated following the manufacturer’s protocol. For a given sample, RNA isolated from each 100 ml aliquot was pooled and concentrated to 100 ml volume over Microcon YM-3 filter units (Millipore) at 14,0006g, 1.5 hour, 4uC, which were loaded inverted into pre-weighed 1.5 ml microcentrifuge tubes and eluted at 10006g, 3 min, 4uC. Tubes plus eluate was weighed on an analytical scale and brought to 100 ml with Elution Buffer. RNA was stored at 280uC.Materials and Methods Cell CultureLNCaP (ATCCH CRL-1740TM) and VCaP [10] human prostate cancer cell lines were cultured in RPMI 1640 and DMEM, respectively, each supplemented with 10 FBS (or under serum-free conditions, as noted), at 37uC in a 5 CO2 incubator. Hypoxic conditions (1 O2) were established in a Thermo Scientific 3595 Incubator (ThermoFisher), with cells maintained under normoxic conditions (20 O2) in parallel.Collection and Processing of Clinical Tissue SectionsLaser-capture micro-dissection (LCM) of frozen-tissue sections. 1315463 Sections of flash-frozen prostate and lymph nodeRNA Isolation from Cultured Cells and Conditioned MediaConditioned media was removed from cells cultured for 24, 48 or 72 hours under normoxic or hypoxic conditions. Cells were washed with 5 ml PBS and lysed on ice directly in the culture dish with 600 ml Lysis/Binding buffer from the mirVana miRNA isolation kit (Ambion). Lysates were harvested manually with a sterile cell scraper and transferred to an RNase2/DNase-free 2 ml microcentrifuge tube. RNA was extracted from cell lysates following the manufacturer’s recommended protocol for total RNA isolation. Cellular debris was removed from a 500 ml aliquot of conditioned media (10 ml total volume) by filtration through a 0.2 mm NanoSep filtration unit (Millipore) at 14,0006g, 5 min, at room temperature. 400 ml filtered sample was combined with 400 ml 2X Denaturing Solution (Ambion) and vortexed. C. elegans spiked-in oligonucleotides were introduced (as a mixture of 25 fmol of each oligonucleotide in 5 ml total volume per liquid sample) after denaturation and used for normalization of variability in RNA isolation across samples as previously described [1]. RNA was extracted from conditioned media lysates using the mirVana PARIS kit (Ambion) following the manufacturer’s recommended protocol for total RNA isolation.Ethics StatementAll clinical samples were obtained from subjects who provided written informed consent. Studies were performed in accordanceobtained from radical prostatectomy and rapid autopsy, respectively, were assessed by a pathologist to define regions of tumor epithelial cells. For laser capture microdissection 5 mm sections of frozen tissue were made on a LeicaTMCM3050S cryostat at 220uC (Leica, Wetzlar, Germany), placed onto PEN Membrane F.