Journal: eLife

Article Title: Unique integrated stress response sensors regulate cancer cell susceptibility when Hsp70 activity is compromised

doi: 10.7554/eLife.64977

Figure Lengend Snippet: ( A ) HER2 (diamonds), TNBC (circles), and luminal (squares and triangles) breast cancer lines were seeded into 96-well plates and treated with increasing doses of MAL3-101 for 72 hr. Viability is expressed as the average of three or more independent experiments, ± SEM. ( B ) MAL3-101-sensitive (MCF7 and MDA MB 231, denoted in blue) and resistant (MDA MB 453 and MDA MB 361, denoted in black) cells were treated with 12 µM MAL3-101 for the indicated times, and lysates were prepared and immunoblotted for cleaved caspase-3, caspase-7, and caspase-8. β-actin serves as a loading control. ( C ) The corresponding fold-increase of the indicated apoptotic markers relative to the DMSO control are plotted, ± SEM (n≥3 for cleaved caspase-3, n=3 for cleaved caspase-7, and n≥4 for cleaved caspase-8). Black asterisks correspond to statistical significance between MDA MB 231 cells (closed circle) and MDA MB 453 and MDA MB 361 (open circle and triangle, respectively), and the red asterisk represents statistical significance between MCF7 (closed triangle) and MDA MB 453 and MDA MB 361 (open circle and triangle) cells; * denotes p<0.05, ** denotes p<0.005. Figure 1—source data 1. Source data for cell viability assay and apoptotic marker accumulation in .

Article Snippet: For the remaining proteins aliquots from the same lysates were instead heated to 37°C for 30 min prior to SDS-PAGE using 4–20% Tris-Glycine gradient gels (XP04202Box, Thermo Fisher Scientific), and after transfer on nitrocellulose membranes (#84–874, Prometheus Laboratories Inc, California), the blots were incubated with anti-cleaved Caspase-8 (18C8, #9496; at 1:1000), anti-BiP (C50B12, #3177S; at 1:1000), anti-Hsp70 (smc-113, StressMarq Biosciences, Victoria, British Columbia; at 1:1000), anti-Hsc/Hsp70 (#4872S; at 1:1000), anti-HER2 (29D8, #2165; at 1:2000), anti-eIF2α (#9722S; at 1:2000), anti-phospho-eIF2α (#9721L; at 1:500), anti-PERK (D11A8, #5683S; at 1:2000), anti-PKR (D7F7, #12297S; at 1:2000), anti-Ire1α (14C10, #3294S; at 1:1000), anti-HRI (MBS2538114, MyBioSource, San Diego, CA; at 1:500) and anti-GCN2 and anti-GCN2 pT899 antibody (ab-134053 and ab-75836, Abcam, Cambtidge, UK; at 1:2000).

Techniques: Viability Assay, Marker

Journal: eLife

Article Title: Unique integrated stress response sensors regulate cancer cell susceptibility when Hsp70 activity is compromised

doi: 10.7554/eLife.64977

Figure Lengend Snippet: Breast cancer cells exhibit a range of sensitivities to MAL3-101, a specific Hsp70 inhibitor. The indicated breast cancer lines were seeded into 96-well plates and treated with increasing doses of the indicated compounds for 72 hr. Viability was measured using the CellTiter-Glo assay. IC 50 values were generate using a sigmoidal nonlinear regression with SigmaPlot 11.0. ND stands for an undetermined value. MAL3-101 sensitivities of Hsp70 inhibitor resistant cells are in bold.

Article Snippet: For the remaining proteins aliquots from the same lysates were instead heated to 37°C for 30 min prior to SDS-PAGE using 4–20% Tris-Glycine gradient gels (XP04202Box, Thermo Fisher Scientific), and after transfer on nitrocellulose membranes (#84–874, Prometheus Laboratories Inc, California), the blots were incubated with anti-cleaved Caspase-8 (18C8, #9496; at 1:1000), anti-BiP (C50B12, #3177S; at 1:1000), anti-Hsp70 (smc-113, StressMarq Biosciences, Victoria, British Columbia; at 1:1000), anti-Hsc/Hsp70 (#4872S; at 1:1000), anti-HER2 (29D8, #2165; at 1:2000), anti-eIF2α (#9722S; at 1:2000), anti-phospho-eIF2α (#9721L; at 1:500), anti-PERK (D11A8, #5683S; at 1:2000), anti-PKR (D7F7, #12297S; at 1:2000), anti-Ire1α (14C10, #3294S; at 1:1000), anti-HRI (MBS2538114, MyBioSource, San Diego, CA; at 1:500) and anti-GCN2 and anti-GCN2 pT899 antibody (ab-134053 and ab-75836, Abcam, Cambtidge, UK; at 1:2000).

Techniques:

Journal: eLife

Article Title: Unique integrated stress response sensors regulate cancer cell susceptibility when Hsp70 activity is compromised

doi: 10.7554/eLife.64977

Figure Lengend Snippet: The cell numbers and autophagy or proteasome inhibitor concentrations used for the cell viability assay in combination with increasing doses of MAL3-101 are shown. The concentrations of bortezomib, CQ, and bafilomycin to induce no greater than 30% of cell death in each line after 72 hr treatment are shown. ND stands for undetermined value.

Article Snippet: For the remaining proteins aliquots from the same lysates were instead heated to 37°C for 30 min prior to SDS-PAGE using 4–20% Tris-Glycine gradient gels (XP04202Box, Thermo Fisher Scientific), and after transfer on nitrocellulose membranes (#84–874, Prometheus Laboratories Inc, California), the blots were incubated with anti-cleaved Caspase-8 (18C8, #9496; at 1:1000), anti-BiP (C50B12, #3177S; at 1:1000), anti-Hsp70 (smc-113, StressMarq Biosciences, Victoria, British Columbia; at 1:1000), anti-Hsc/Hsp70 (#4872S; at 1:1000), anti-HER2 (29D8, #2165; at 1:2000), anti-eIF2α (#9722S; at 1:2000), anti-phospho-eIF2α (#9721L; at 1:500), anti-PERK (D11A8, #5683S; at 1:2000), anti-PKR (D7F7, #12297S; at 1:2000), anti-Ire1α (14C10, #3294S; at 1:1000), anti-HRI (MBS2538114, MyBioSource, San Diego, CA; at 1:500) and anti-GCN2 and anti-GCN2 pT899 antibody (ab-134053 and ab-75836, Abcam, Cambtidge, UK; at 1:2000).

Techniques: Viability Assay

Journal: eLife

Article Title: Unique integrated stress response sensors regulate cancer cell susceptibility when Hsp70 activity is compromised

doi: 10.7554/eLife.64977

Figure Lengend Snippet: Breast cancer cells exhibit a range of sensitivities to MAL3-101 in the presence of either autophagy or proteasome inhibitors. Cells were seeded into 96-well plates and treated with increasing doses of MAL3-101 in the presence or absence of subcritical doses of bortezomib (proteasome inhibitor), or CQ or bafilomycin (autophagy inhibitors) for 72 hr. Viability was measured using the CellTiter-Glo assay. IC 50 values were generate using a sigmoidal nonlinear regression with SigmaPlot 11.0. ND stands for undetermined value. MAL3-101 resistant cells are highlighted in yellow.

Article Snippet: For the remaining proteins aliquots from the same lysates were instead heated to 37°C for 30 min prior to SDS-PAGE using 4–20% Tris-Glycine gradient gels (XP04202Box, Thermo Fisher Scientific), and after transfer on nitrocellulose membranes (#84–874, Prometheus Laboratories Inc, California), the blots were incubated with anti-cleaved Caspase-8 (18C8, #9496; at 1:1000), anti-BiP (C50B12, #3177S; at 1:1000), anti-Hsp70 (smc-113, StressMarq Biosciences, Victoria, British Columbia; at 1:1000), anti-Hsc/Hsp70 (#4872S; at 1:1000), anti-HER2 (29D8, #2165; at 1:2000), anti-eIF2α (#9722S; at 1:2000), anti-phospho-eIF2α (#9721L; at 1:500), anti-PERK (D11A8, #5683S; at 1:2000), anti-PKR (D7F7, #12297S; at 1:2000), anti-Ire1α (14C10, #3294S; at 1:1000), anti-HRI (MBS2538114, MyBioSource, San Diego, CA; at 1:500) and anti-GCN2 and anti-GCN2 pT899 antibody (ab-134053 and ab-75836, Abcam, Cambtidge, UK; at 1:2000).

Techniques: