CARD10 cleavage by MALT1 restricts lung carcinoma growth in vivo

Area of Science:

• Cellular signaling pathways
• Molecular mechanisms of cancer
• NF-κB regulation

Background:

• CARD-CC complexes, including BCL10 and MALT1, are critical signaling hubs.
• MALT1 regulates NF-κB activation via scaffolding and substrate cleavage.
• Dysregulation of this pathway in lymphocytes causes lymphoproliferative disorders, and CARD10 is implicated in cancer.

Purpose of the Study:

• To investigate the regulation of CARD10 in non-hematopoietic cells.
• To identify MALT1 substrates in non-hematopoietic cells.
• To elucidate the role of CARD10 cleavage in tumorigenicity.

Main Methods:

• Identification of CARD10 as a MALT1 substrate.
• Analysis of CARD10 cleavage at R587 by MALT1.
• In vitro studies using A549 lung tumor cells to assess IL-6 and extracellular matrix component levels.
• In vivo mouse xenograft model to evaluate tumor growth.

Main Results:

• CARD10 was identified as the first MALT1 substrate in non-hematopoietic cells.
• MALT1-mediated cleavage of CARD10 at R587 reduces its NF-κB activating capacity.
• Inhibition of CARD10 cleavage increased IL-6 and extracellular matrix production in vitro.
• Preventing CARD10 cleavage resulted in accelerated tumor growth in a mouse model.

Conclusions:

• CARD10 cleavage by MALT1 is a novel regulatory mechanism in non-hematopoietic cells.
• This cleavage event acts as a tumor-suppressive mechanism by limiting NF-κB signaling.
• CARD10 cleavage by MALT1 may represent an intrinsic control of tumorigenicity.