MMP2 activity or expression was not affected by repression of HSPA4 or HSPA14 in H1299NBS1 cells and the correlation of HSF4b expression with HSPA4/HSPA14 expression. (A) & (B) Gelatin zymography of the conditioned medium of H1299NBS1 control vs. H1299NBS1-HSPA4i clones (A) or H1299NBS1-HSPA14i clones (B), which was shown in the first lane of each panel. Both pro-MMP2 and active MMP2 activity were stained. The second to the fourth lanes showed the RT-PCR analysis of MMP2, HSPA4/HSPA14, and GAPDH levels in H1299NBS1 control vs. H1299NBS1-HSPA4i clones (A) or H1299NBS1-HSPA14i clones (B). (C) RT-PCR analysis showed the induction of HSF4b, but not HSF1 or HSF2, by NBS1 overexpression in two different cell lines (FADU control vs. FADUNBS1, H1299 control vs. H1299NBS1).