Apalutamide and autophagy inhibition in a xenograft mouse model of human prostate cancer

© 2022. The Author(s)..

BACKGROUND: Apalutamide (APA) is a next-generation androgen receptor antagonist for the treatment of advanced prostate cancer. We have previously shown that upregulation of autophagy is one of the mechanisms by which prostate cancer (PC) cells survive APA anti-tumor treatment in vitro. Therefore, we investigated the characteristics of the autophagic response to APA treatment, alone and in combination with autophagy inhibition, in an in vivo model.

METHODS: Tumor cells were injected into previously castrated nude mice. Four groups of mice bearing LNCaP xenografts were treated with daily intraperitoneal (i.p.) injections of vehicle (control), APA (10 mg/kg), APA (10 mg/kg) + Chl (Chloroquine, 10 mg/kg) or Chl (10 mg/kg). The animals of each treatment group (3/treatment) were kept for the duration of 2 and 3 weeks. At the end of the experiments, the animals were sacrificed and all samples assessed for tumor weight and size, histological analysis, immunoblotting (WES) and immunofluorescence.

RESULTS: The tumor weight was significantly reduced in mice treated with APA + Chl (203.2 ± 5.0, SEM, P = 0.0066) compared to vehicle control (380.4 ± 37.0). Importantly, the combined treatment showed a higher impact on tumor weight than APA (320.4 ± 45.5) or Chl (337.9 ± 35) alone. The mice treated with the combination of APA + Chl exhibited a reduced expression of ATG5 (autophagy-related five protein), Beclin 1 and LC3 punctuations and an increase in P62 as visualized by immunofluorescence and WES. In addition, Ki-67 nuclear staining was detected in all samples however reduced in APA + Chl (58%) compared to vehicle control (100%). The reduction in Ki-67 protein was associated with an increase in caspase 3 and endothelial CD31 protein expression.

CONCLUSION: These data demonstrate that a treatment with APA + Chl leads to reduced autophagy levels and to tumor suppression compared to the APA monotherapy. Hence, the increased antitumor effect of APA in combination with autophagy inhibitors might provide a new therapeutic approach potentially translatable to patients.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:148

Enthalten in:

Journal of cancer research and clinical oncology - 148(2022), 12 vom: 03. Dez., Seite 3351-3360

Sprache:

Englisch

Beteiligte Personen:

Eberli, Daniel [VerfasserIn]
Kranzbühler, Benedikt [VerfasserIn]
Prause, Lukas [VerfasserIn]
Baumgartner, Valentin [VerfasserIn]
Preda, Sheryl [VerfasserIn]
Sousa, Rosa [VerfasserIn]
Lehner, Fabienne [VerfasserIn]
Salemi, Souzan [VerfasserIn]

Links:

Volltext

Themen:

886U3H6UFF
Androgen Receptor Antagonists
Apalutamide
Autophagy
Beclin-1
Caspase 3
Chloroquine
EC 3.4.22.-
In vivo
Journal Article
Ki-67 Antigen
Prostate cancer

Anmerkungen:

Date Completed 26.10.2022

Date Revised 28.03.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1007/s00432-022-04059-1

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM342726951