Inhibition of the Tcf/beta-catenin complex increases apoptosis and impairs adrenocortical tumor cell proliferation and adrenal steroidogenesis.

Abstract

BACKGROUND:

To date, there is no effective therapy for patients with advanced/metastatic adrenocortical cancer (ACC). The activation of the Wnt/beta-catenin signaling is frequent in ACC and this pathway is a promising therapeutic target.

AIM:

To investigate the effects of the inhibition of the Wnt/beta-catenin in ACC cells.

METHODS:

Adrenal (NCI-H295 and Y1) and non-adrenal (HeLa) cell lines were treated with PNU-74654 (5-200 μM) for 24-96 h to assess cell viability (MTS-based assay), apoptosis (Annexin V), expression/localization of beta-catenin (qPCR, immunofluorescence, immunocytochemistry and western blot), expression of beta-catenin target genes (qPCR and western blot), and adrenal steroidogenesis (radioimmunoassay, qPCR and western blot).

RESULTS:

In NCI-H295 cells, PNU-74654 significantly decreased cell proliferation 96 h after treatment, increased early and late apoptosis, decreased nuclear beta-catenin accumulation, impaired CTNNB1/beta-catenin expression and increased beta-catenin target genes 48 h after treatment. No effects were observed on HeLa cells. In NCI-H295 cells, PNU-74654 decreased cortisol, testosterone and androstenedione secretion 24 and 48 h after treatment. Additionally, in NCI-H295 cells, PNU-74654 decreased SF1 and CYP21A2 mRNA expression as well as the protein levels of STAR and aldosterone synthase 48 h after treatment. In Y1 cells, PNU-74654 impaired corticosterone secretion 24 h after treatment but did not decrease cell viability.

CONCLUSIONS:

Blocking the Tcf/beta-catenin complex inhibits the Wnt/beta-catenin signaling in adrenocortical tumor cells triggering increased apoptosis, decreased cell viability and impairment of adrenal steroidogenesis. These promising findings pave the way for further experiments inhibiting the Wnt/beta-catenin pathway in pre-clinical models of ACC. The inhibition of this pathway may become a promising adjuvant therapy for patients with ACC.

• Authors: Letícia F Leal, Ana Carolina Bueno, Débora C Gomes, Rafael Abduch, Margaret de Castro, Sonir R Antonini
• Journal: Oncotarget (Oncotarget) Vol. 6 Issue 40 Pg. 43016-32 (Dec 15 2015) ISSN: 1949-2553 [Electronic] United States
• PMID: 26515592 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents
• T Cell Transcription Factor 1
• TCF7 protein, human
• beta Catenin

Topics

• Adrenal Cortex Neoplasms (pathology)
• Antineoplastic Agents (pharmacology)
• Apoptosis (drug effects)
• Blotting, Western
• Cell Line, Tumor
• Cell Proliferation (drug effects)
• Flow Cytometry
• Fluorescent Antibody Technique
• Humans
• Immunohistochemistry
• Radioimmunoassay
• Real-Time Polymerase Chain Reaction
• T Cell Transcription Factor 1 (antagonists & inhibitors)
• Wnt Signaling Pathway (drug effects)
• beta Catenin (antagonists & inhibitors)