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. Author manuscript; available in PMC: 2024 Jan 14.
Published in final edited form as: Mol Cancer Res. 2020 Apr 29;18(8):1202–1217. doi: 10.1158/1541-7786.MCR-19-1162

Figure 7. Mechanism of action of miR-4454 through BAG5 and SPARC.

Figure 7.

(A) The OC cells (OVCAR3, OVCAR4 and Kuramochi) were transfected with pre-miR-4454 or scrambled control oligo (Scr) (left panel) or with BAG5 siRNA or scrambled control oligos (Scr) (right panel). Cells were allowed to grow for 48 h and then lysed in RIPA buffer. Proteins were separated by 4–20% gradient SDS-PAGE and transferred to nitrocellulose membrane, probed with BAG5, cleaved PARP, cleaved caspase-3 and p53 antibodies. Representative blots from 3 independent experiments are shown. (B) OVCAR3, OVCAR4 or Kuramochi cells were transfected with pre-miR-4454 or scrambled control oligo (Scr) (left panel) or with SPARC siRNA or scrambled control oligos (Scr) (right panel). Cells were allowed to grow for 48 h and then lysed in RIPA buffer. Proteins were separated by 4–20% gradient SDS-PAGE and transferred to nitrocellulose membrane, probed with SPARC, phosphorylated FAK at Tyr397 (pFAK) and total FAK antibodies. Representative blots from 3 independent experiments are shown. (C) Schematic overview of findings. Paracrine signals from microenvironmental fibroblasts lead to downregulation of miR-4454 in metastasizing OC cells. The downregulation of miR-4454 promotes metastatic colonization through the concomitant increased expression of its targets SPARC and BAG5, which help by activating FAK, promoting mutant p53 gain of function by its stabilization and inhibiting apoptosis respectively.