Targeting Acid Ceramidase Inhibits Glioblastoma Cell Migration through Decreased AKT Signaling.

in Cells by Cyntanna C Hawkins, Amber B Jones, Emily R Gordon, Sarah E Williford, Yuvika Harsh, Julia K Ziebro, Catherine J Landis, Sajina Gc, David K Crossman, Sara J Cooper, Sasanka Ramanadham, Ninh Doan, Anita B Hjelmeland

TLDR

  • The study shows that inhibiting acid ceramidase (ASAH1) in glioblastoma (GBM) cells reduces their ability to migrate and invasively spread.
  • The small molecule inhibitor carmofur is a potential therapeutic option for GBM treatment, targeting the key regulator ASAH1.
  • Future research should investigate the clinical efficacy and safety of ASAH1 inhibition in GBM patients.

Abstract

Glioblastoma (GBM) remains one of the most aggressive cancers, partially due to its ability to migrate into the surrounding brain. The sphingolipid balance, or the balance between ceramides and sphingosine-1-phosphate, contributes to the ability of GBM cells to migrate or invade. Of the ceramidases which hydrolyze ceramides, acid ceramidase (ASAH1) is highly expressed in GBM samples compared to non-tumor brain. ASAH1 expression also correlates with genes associated with migration and focal adhesion. To understand the role of ASAH1 in GBM migration, we utilized shRNA knockdown and observed decreased migration that did not depend upon changes in growth. Next, we inhibited ASAH1 using carmofur, a clinically utilized small molecule inhibitor. Inhibition of ASAH1 by carmofur blocks in vitro migration of U251 (GBM cell line) and GBM cells derived from patient-derived xenografts (PDXs). RNA-sequencing suggested roles for carmofur in MAPK and AKT signaling. We found that carmofur treatment decreases phosphorylation of AKT, but not of MAPK. The decrease in AKT phosphorylation was confirmed by shRNA knockdown of ASAH1. Our findings substantiate ASAH1 inhibition using carmofur as a potential clinically relevant treatment to advance GBM therapeutics, particularly due to its impact on migration.

Overview

  • The study focuses on the role of acid ceramidase (ASAH1) in glioblastoma (GBM) migration, a crucial aspect of the disease's aggression.
  • The study utilized shRNA knockdown and a small molecule inhibitor, carmofur, to inhibit ASAH1 and examine its effects on GBM migration.
  • The primary objective is to understand the therapeutic potential of ASAH1 inhibition in GBM, particularly in reducing tumor migration.

Comparative Analysis & Findings

  • Inhibition of ASAH1 using shRNA knockdown and carmofur resulted in decreased GBM cell migration, independent of changes in growth.
  • RNA-sequencing revealed roles for carmofur in MAPK and AKT signaling, with a decrease in AKT phosphorylation confirmed by shRNA knockdown of ASAH1.
  • The study found that ASAH1 inhibition using carmofur blocks in vitro migration of GBM cells and decreases phosphorylation of AKT, but not MAPK.

Implications and Future Directions

  • The findings support ASAH1 inhibition using carmofur as a potential clinically relevant treatment to advance GBM therapeutics, particularly in reducing tumor migration.
  • Future studies should investigate the mechanistic basis of ASAH1-mediated migration and focus on optimizing carmofur treatment strategies.
  • Long-term studies are needed to evaluate the efficacy and safety of ASAH1 inhibition in GBM patients.
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