BCL-XL inhibitors enhance the apoptotic efficacy of BRAF inhibitors in BRAFV600E colorectal cancer

© 2024. The Author(s)..

Metastatic BRAFV600E colorectal cancer (CRC) carries an extremely poor prognosis and is in urgent need of effective new treatments. While the BRAFV600E inhibitor encorafenib in combination with the EGFR inhibitor cetuximab (Enc+Cet) was recently approved for this indication, overall survival is only increased by 3.6 months and objective responses are observed in only 20% of patients. We have found that a limitation of Enc+Cet treatment is the failure to efficiently induce apoptosis in BRAFV600E CRCs, despite inducing expression of the pro-apoptotic protein BIM and repressing expression of the pro-survival protein MCL-1. Here, we show that BRAFV600E CRCs express high basal levels of the pro-survival proteins MCL-1 and BCL-XL, and that combining encorafenib with a BCL-XL inhibitor significantly enhances apoptosis in BRAFV600E CRC cell lines. This effect was partially dependent on the induction of BIM, as BIM deletion markedly attenuated BRAF plus BCL-XL inhibitor-induced apoptosis. As thrombocytopenia is an established on-target toxicity of BCL-XL inhibition, we also examined the effect of combining encorafenib with the BCL-XL -targeting PROTAC DT2216, and the novel BCL-2/BCL-XL inhibitor dendrimer conjugate AZD0466. Combining encorafenib with DT2216 significantly increased apoptosis induction in vitro, while combining encorafenib with AZD0466 was well tolerated in mice and further reduced growth of BRAFV600E CRC xenografts compared to either agent alone. Collectively, these findings demonstrate that combined BRAF and BCL-XL inhibition significantly enhances apoptosis in pre-clinical models of BRAFV600E CRC and is a combination regimen worthy of clinical investigation to improve outcomes for these patients.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:15

Enthalten in:

Cell death & disease - 15(2024), 3 vom: 01. März, Seite 183

Sprache:

Englisch

Beteiligte Personen:

Jenkins, Laura J [VerfasserIn]
Luk, Ian Y [VerfasserIn]
Chionh, Fiona [VerfasserIn]
Tan, Tao [VerfasserIn]
Needham, Kristen [VerfasserIn]
Ayton, Jamieson [VerfasserIn]
Reehorst, Camilla M [VerfasserIn]
Vukelic, Natalia [VerfasserIn]
Sieber, Oliver M [VerfasserIn]
Mouradov, Dmitri [VerfasserIn]
Gibbs, Peter [VerfasserIn]
Williams, David S [VerfasserIn]
Tebbutt, Niall C [VerfasserIn]
Desai, Jayesh [VerfasserIn]
Hollande, Frédéric [VerfasserIn]
Dhillon, Amardeep S [VerfasserIn]
Lee, Erinna F [VerfasserIn]
Merino, Delphine [VerfasserIn]
Fairlie, W Douglas [VerfasserIn]
Mariadason, John M [VerfasserIn]

Links:

Volltext

Themen:

8L7891MRB6
Antineoplastic Agents
BRAF protein, human
Bcl-X Protein
Carbamates
DT2216
EC 2.7.11.1
Encorafenib
Journal Article
Myeloid Cell Leukemia Sequence 1 Protein
Protein Kinase Inhibitors
Proto-Oncogene Proteins B-raf
Sulfonamides

Anmerkungen:

Date Completed 04.03.2024

Date Revised 14.03.2024

published: Electronic

Citation Status MEDLINE

doi:

10.1038/s41419-024-06478-z

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM369191773