PAQR8 promotes breast cancer recurrence and confers resistance to multiple therapies

© 2022. The Author(s)..

BACKGROUND: Breast cancer mortality is principally due to recurrent disease that becomes resistant to therapy. We recently identified copy number (CN) gain of the putative membrane progesterone receptor PAQR8 as one of four focal CN alterations that preferentially occurred in recurrent metastatic tumors compared to primary tumors in breast cancer patients. Whether PAQR8 plays a functional role in cancer is unknown. Notably, PAQR8 CN gain in recurrent tumors was mutually exclusive with activating ESR1 mutations in patients treated with anti-estrogen therapies and occurred in > 50% of both patients treated with anti-estrogen therapies and those treated with chemotherapy or anti-Her2 agents.

METHODS: We used orthotopic mouse models to determine whether PAQR8 overexpression or deletion alters breast cancer dormancy or recurrence following therapy. In vitro studies, including assays for colony formation, cell viability, and relative cell fitness, were employed to identify effects of PAQR8 in the context of therapy. Cell survival and proliferation were quantified by immunofluorescence staining for markers of apoptosis and proliferation. Sphingolipids were quantified by liquid chromatography-high resolution mass spectrometry.

RESULTS: We show that PAQR8 is necessary and sufficient for efficient mammary tumor recurrence in mice, spontaneously upregulated and CN gained in recurrent tumors that arise following therapy in multiple mouse models, and associated with poor survival following recurrence as well as poor overall survival in breast cancer patients. PAQR8 promoted resistance to therapy by enhancing tumor cell survival following estrogen receptor pathway inhibition by fulvestrant or estrogen deprivation, Her2 pathway blockade by lapatinib or Her2 downregulation, and treatment with chemotherapeutic agents. Pro-survival effects of PAQR8 were mediated by a Gi protein-dependent reduction in cAMP levels, did not require progesterone, and involved a PAQR8-dependent decrease in ceramide levels and increase in sphingosine-1-phosphate levels, suggesting that PAQR8 may possess ceramidase activity.

CONCLUSIONS: Our data provide in vivo evidence that PAQR8 plays a functional role in cancer, implicate PAQR8, cAMP, and ceramide metabolism in breast cancer recurrence, and identify a novel mechanism that may commonly contribute to the acquisition of treatment resistance in breast cancer patients.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:25

Enthalten in:

Breast cancer research : BCR - 25(2023), 1 vom: 03. Jan., Seite 1

Sprache:

Englisch

Beteiligte Personen:

Chen, Saisai [VerfasserIn]
Paul, Matt R [VerfasserIn]
Sterner, Christopher J [VerfasserIn]
Belka, George K [VerfasserIn]
Wang, Dezhen [VerfasserIn]
Xu, Peining [VerfasserIn]
Sreekumar, Amulya [VerfasserIn]
Pan, Tien-Chi [VerfasserIn]
Pant, Dhruv K [VerfasserIn]
Makhlin, Igor [VerfasserIn]
DeMichele, Angela [VerfasserIn]
Mesaros, Clementina [VerfasserIn]
Chodosh, Lewis A [VerfasserIn]

Links:

Volltext

Themen:

0VUA21238F
22X328QOC4
Breast cancer
EC 2.7.10.1
Endocrine therapy
Estrogens
Fulvestrant
Journal Article
Lapatinib
Paqr8 protein, mouse
Receptor, ErbB-2
Receptors, Progesterone
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Translational research
Treatment resistance
Tumor recurrence

Anmerkungen:

Date Completed 05.01.2023

Date Revised 28.02.2023

published: Electronic

Citation Status MEDLINE

doi:

10.1186/s13058-022-01559-3

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM351083588