lncRNA BORG:TRIM28 Complexes Drive Metastatic Progression by Inducing α6 Integrin/CD49f Expression in Breast Cancer Stem Cells

©2021 The Authors; Published by the American Association for Cancer Research..

Triple-negative breast cancer (TNBC) is the most lethal subtype of breast cancer, with its aggressive phenotype being attributed to chemotherapy resistance, metastatic dissemination, and rapid disease recurrence. Breast cancer stem cells (BCSC) are significant contributors to tumor initiation, as well as to the acquisition of aggressive tumorigenic phenotypes, namely due to their ability to self-replicate and to produce heterogeneous differentiated tumor cells. To elucidate the underlying mechanisms that drive BCSC tumorigenicity in TNBC, we identified the long noncoding RNA (lncRNA) B MP/ O P- R esponsive G ene (BORG) as an enhancer of BCSC phenotypes. Indeed, we found BORG expression to: (i) correlate with stem cell markers Nanog, Aldh1a3, and Itga6 (α6 integrin/CD49f); (ii) enhance stem cell phenotypes in murine and human TNBC cells, and (iii) promote TNBC tumor initiation in mice. Mechanistically, BORG promoted BCSC phenotypes through its ability to interact physically with the E3 SUMO ligase TRIM28. Moreover, TRIM28 binding was observed in the promoter region of Itga6, whose genetic inactivation prevented BORG:TRIM28 complexes from: (i) inducing BCSC self-renewal and expansion in vitro, and (ii) eliciting BCSC metastatic outgrowth in the lungs of mice. Collectively, these findings implicate BORG:TRIM28 complexes as novel drivers of BCSC phenotypes in developing and progressing TNBCs. IMPLICATIONS: This work establishes the lncRNA BORG as a driver of BCSC phenotypes and the aggressive behaviors of TNBCs, events critically dependent upon the formation of BORG:TRIM28 complexes and expression of α6 integrin.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:19

Enthalten in:

Molecular cancer research : MCR - 19(2021), 12 vom: 08. Dez., Seite 2068-2080

Sprache:

Englisch

Beteiligte Personen:

Parker, Kimberly A [VerfasserIn]
Gooding, Alex J [VerfasserIn]
Valadkhan, Saba [VerfasserIn]
Schiemann, William P [VerfasserIn]

Links:

Volltext

Themen:

EC 2.3.2.27
Integrin alpha6
Journal Article
RNA, Long Noncoding
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Trim28 protein, mouse
Tripartite Motif-Containing Protein 28

Anmerkungen:

Date Completed 25.03.2022

Date Revised 25.03.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1158/1541-7786.MCR-21-0137

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM330394029