Trop-2, Na+/K+ ATPase, CD9, PKCα, cofilin assemble a membrane signaling super-complex that drives colorectal cancer growth and invasion.
Oncogene
; 41(12): 1795-1808, 2022 03.
Article
in En
| MEDLINE
| ID: mdl-35132180
ABSTRACT
Trop-2 is a transmembrane signal transducer that is overexpressed in most human cancers, and drives malignant progression. To gain knowledge on the higher-order molecular mechanisms that drive Trop-2 signaling, we applied next-generation sequencing, proteomics, and high-resolution microscopy to models and primary cases of human colorectal cancer (CRC). We had previously shown that Trop-2 induces a Ca2+ signal. We reveal here that Trop-2 binds the cell membrane Na+/K+-ATPase, and that clustering of Trop-2 induces an intracellular Ca2+ rise followed by membrane translocation of PKCα, which in turn phosphorylates the Trop-2 cytoplasmic tail. This feed-forward signaling is promoted by the binding of Trop-2 to the PKCα membrane-anchor CD9. CRISPR-based inactivation of CD9 in CRC cells shows that CD9 is required by Trop-2 for recruiting PKCα and cofilin-1 to the cell membrane. This induces malignant progression through proteolytic cleavage of E-cadherin, remodeling of the ß-actin cytoskeleton, and activation of Akt and ERK. The interaction between Trop-2 and CD9 was validated in vivo in murine models of CRC growth and invasion. Overexpression of the components of this Trop-2-driven super-complex significantly worsened disease-free and overall survival of CRC patients, supporting a pivotal relevance in CRC malignant progression. Our findings demonstrate a previously unsuspected layer of cancer growth regulation, which is dormant in normal tissues, and is activated by Trop-2 in cancer cells.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Colorectal Neoplasms
/
Protein Kinase C-alpha
Type of study:
Prognostic_studies
Limits:
Animals
/
Humans
Language:
En
Journal:
Oncogene
Journal subject:
BIOLOGIA MOLECULAR
/
NEOPLASIAS
Year:
2022
Document type:
Article
Affiliation country:
Italy