FIGURE 3.

HSP47 interferes with both calreticulin/SERCA2 interaction and IRE1α/IP₃R interaction in pancreatic cancer cells. A, Expression of calreticulin (CALR) and IRE1α protein in human PDAC cell lines. GAPDH was used as an internal control. B, Expression of CALR and IRE1α protein in HSP47 KO PDAC cells (HSP47 KO PANC1 cells and HSP47 KO MIA‐PaCa 2 cells). C, Interaction of HSP47 with CALR and IRE1α in PANC1 cells expressing HSP47‐Myc after treatment with gemcitabine (10 μmol/L). D, Interaction of CALR with SERCA2 in HSP47 KO PANC1 cells expressing SERCA2‐Myc. E, Interaction of CALR with SERCA2 in HSP47 KO PANC1 cells expressing SERCA2‐Myc after treatment with gemcitabine (10 μmol/L). F, Interaction of CALR with SERCA2 in HSP47 KO PANC1 cells expressing SERCA2‐Myc and reconstituting HSP47‐GFP expression after treatment with gemcitabine (10 μmol/L). G, The binding ratio of CALR (IP) /SERCA2‐Myc (IP) was determined by using NIH ImageJ software. *, P < .05. H, Interaction of IRE1α with IP₃R in HSP47 KO PANC1 cells expressing IRE1α‐Myc after treatment with gemcitabine (10 μmol/L). (I) Interaction of IRE1α with IP₃R in HSP47 KO PANC1 cells expressing IRE1α‐Myc and reconstituting HSP47‐GFP expression after treatment with gemcitabine (10 μmol/L)