title: Silencing mutated β-catenin inhibits cell proliferation and stimulates apoptosis in the adrenocortical cancer cell line H295R.
abstract: BACKGROUND
  Adrenocortical carcinoma (ACC) is a rare and highly aggressive endocrine neoplasm, with limited therapeutic options. Activating β-catenin somatic mutations are found in ACC and have been associated with a poor clinical outcome. In fact, activation of the Wnt/β-catenin signaling pathway seems to play a major role in ACC aggressiveness, and might, thus, represent a promising therapeutic target.
  
  
  OBJECTIVE
  Similar to patient tumor specimen the H295 cell line derived from an ACC harbors a natural activating β-catenin mutation. We herein assess the in vitro and in vivo effect of β-catenin inactivation using a doxycyclin (dox) inducible shRNA plasmid in H295R adrenocortical cancer cells line (clone named shβ).
  
  
  RESULTS
  Following dox treatment a profound reduction in β-catenin expression was detectable in shβ clones in comparison to control clones (Ctr). Accordingly, we observed a decrease in Wnt/βcatenin-dependent luciferase reporter activity as well as a decreased expression of AXIN2 representing an endogenous β-catenin target gene. Concomitantly, β-catenin silencing resulted in a decreased cell proliferation, cell cycle alterations with cell accumulation in the G1 phase and increased apoptosis in vitro. In vivo, on established tumor xenografts in athymic nude mice, 9 days of β-catenin silencing resulted in a significant reduction of CTNNB1 and AXIN2 expression. Moreover, continous β-catenin silencing, starting 3 days after tumor cell inoculation, was associated with a complete absence of tumor growth in the shβ group while tumors were present in all animals of the control group.
  
  
  CONCLUSIONS
  In summary, these experiments provide evidences that Wnt/β-catenin pathway inhibition in ACC is a promising therapeutic target.
authors: Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France.
authors: Sébastien
authors: S
authors: Gaujoux
authors: Constanze
authors: C
authors: Hantel
authors: Pierre
authors: P
authors: Launay
authors: Stéphane
authors: S
authors: Bonnet
authors: Karine
authors: K
authors: Perlemoine
authors: Lucile
authors: L
authors: Lefèvre
authors: Marine
authors: M
authors: Guillaud-Bataille
authors: Felix
authors: F
authors: Beuschlein
authors: Frédérique
authors: F
authors: Tissier
authors: Jérôme
authors: J
authors: Bertherat
authors: Marthe
authors: M
authors: Rizk-Rabin
authors: Bruno
authors: B
authors: Ragazzon
mesh_terms: D000306:Adrenal Cortex Neoplasms / Q000235:genetics* / Q000378:metabolism; D018268:Adrenocortical Carcinoma / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D002453:Cell Cycle / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004195:Disease Models, Animal; D005260:Female; D020868:Gene Silencing; D006801:Humans; D051379:Mice; D009154:Mutation; D034622:RNA Interference; D015398:Signal Transduction; D051820:TCF Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D014183:Transplantation, Heterologous; D051153:Wnt Proteins / Q000378:metabolism; D051176:beta Catenin / Q000235:genetics*
chemical_list: D051820:TCF Transcription Factors; D051153:Wnt Proteins; D051176:beta Catenin