ECE2024 Poster Presentations Adrenal and Cardiovascular Endocrinology (95 abstracts)
Therapeutic potential of targeting the FLNA-regulated Wee1 kinase in adrenocortical carcinomas
Emanuela Esposito 1,2 , Rosa Catalano 1 , Emma Nozza 1,2 , Giusy Marra 1 , Sara Maioli 1,3 , Genesio DiMuro 1,4 , Anna Maria Barbieri 1 , Hantel Constanze 5,6 , Guido DiDalmazi 7,8 , JensAlbrecht Ernst Geginat 1 , Elisa Cassinotti 9 , Ludovica Baldari 9 , Serena Palmieri 10 , Alessandra Mangone 10 , Emanuele Ferrante 10 , Giovanna Mantovani 1,10 & Erika Peverelli 1,10
1University of Milan, Department of Clinical Sciences and Community Health, Milan, Italy; 2University of Milan, PhD Programme in Experimental Medicine, MIlan, Italy; 3University of Milan, PhD Programme in Translational Medicine, Milan, Italy; 4University Sapienza of Rome, PhD Programme in Endocrinological Sciences, Rome, Italy; 5University Hospital Zurich (USZ) and University of Zurich (UZH), Department of Endocrinology, Diabetology and Clinical Nutrition, Zurich, Switzerland; 6University Hospital Carl Gustav Carus Dresden, Medizinische Klinik und Poliklinik III, Dresden, Germany; 7IRCCS Azienda Ospedaliero-Universitaria di Bologna, Endocrinology and Prevention and Care of Diabetes Unit, Bologna, Italy; 8Alma Mater University of Bologna, Department of Medical and Surgical Sciences, Bologna, Italy; 9Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Department of Surgery, Milan, Italy; 10Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Endocrinology Unit, Milan, Italy
The cytoskeletal acting-binding protein filamin A (FLNA) is poorly expressed in adrenocortical carcinomas (ACC) compared to adenomas (ACA), and this might contribute to sustain the increased cell proliferation by upregulating IGF1R and its downstream signaling. An increased expression of the CDK1 kinase Wee1, a leading gatekeeper for G2/M transition, was shown in mouse neural progenitor cells after loss of FLNA. Wee1 is highly expressed in several tumor types and its pharmacological inhibitor AZD1775 is currently undergoing clinical trials. This project aims to investigate Wee1 expression in ACC, its regulation by FLNA, the anti-tumor effects of Wee1 inhibitor AZD1775, and the impact of FLNA levels on its efficacy in human H295R and MUC-1 cell lines. The analysis of FLNA and Wee1 protein expression in 6 ACC and 8 normal adrenal tissues revealed that ACC express increased levels of Wee1 (0.3-fold(0.2) vs 0.02-fold(0.05), P<0.001), while lower levels of FLNA (0.4-fold(0.1) vs 2.1-fold(1.7), P<0.05). FLNA silencing induced an increase of about 1.6-fold of Wee1 protein expression in MUC-1 and in primary ACC cultured cells. Accordingly, p-CDK1 and cyclin B1 levels were shown to be higher in FLNA-silenced MUC-1 cells. On the other hand, decreased Wee1 levels (0.4-fold(0.2), P<0.001), as well as those of p-CDK1 and cyclin B1, resulted after FLNA overexpression. Lactacystin treatment reverted Wee1 reduction in FLNA-transfected MUC-1 cells, suggesting that FLNA has a role in promoting Wee1 proteasomal degradation. AZD1775 treatment induced a dose-dependent reduction of cell proliferation in MUC-1 (−91(15%), P<0.001 vs bas at 500 nM), H295R (−52(28%), P<0.05 at 500 nM), and in primary cultured cells derived from 2 ACC (−86(3%), P<0.05 at 1 μM). In MUC-1, Wee1 inhibition increased both the early apoptotic (5.7-fold(2.9), P<0.01 at 1 μM) and necrotic (2.7-fold(3.1), P<0.05 at 1 μM) cell subpopulations. Furthermore, FLNA knockdown increased AZD1775 efficacy in reducing cell proliferation in MUC-1 (−85(8.0%) for FLNA siRNA vs 72(6.4%) for C-siRNA, P<0.01 at 250 nM) and in primary ACC cultured cells (−41.4 for FLNA siRNA vs −20.5 for C-siRNA, P<0.01 at 100 nM). Similarly, it also potentiated AZD1775 pro-apoptotic effect by increasing the early apoptotic cell subpopulation (3.1-fold(2.6) for FLNA siRNA vs 1.8-fold(2.1) for C-siRNA, P<0.05 at 500 nM). In conclusion, this work demonstrates that FLNA regulates Wee1 expression by promoting its proteasomal degradation, suggesting that the low levels of FLNA frequently found in ACC lead to an increase of Wee1 with consequent cancer cells growth. Moreover, it proposes Wee1 inhibition as a new potential therapeutic approach for ACC, particularly for those lacking FLNA.
Article tools
My recent searches
My recently viewed abstracts
Authors
Endocrine Abstracts
ISSN 1470-3947 (print) | ISSN 1479-6848 (online)
© Bioscientifica 2024 |
Privacy policy |
Cookie settings
BiosciAbstracts
Bioscientifica Abstracts is the gateway to a series of products that provide a permanent, citable record of abstracts for biomedical and life science conferences.
Find out more