Loss of Smad4 promotes aggressive lung cancer metastasis by de-repression of PAK3 via miRNA regulation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34381046.
- Also identified by DOI 10.1038/s41467-021-24898-9 and PMC identifier 8357888.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
SMAD4 is mutated in human lung cancer, but the underlying mechanism by which Smad4 loss-of-function (LOF) accelerates lung cancer metastasis is yet to be elucidated. Here, we generate a highly aggressive lung cancer mouse model bearing conditional Kras<sup>G12D</sup>, p53<sup>fl/fl</sup> LOF and Smad4<sup>fl/fl</sup> LOF mutations (SPK), showing a much higher incidence of tumor metastases than the Kras<sup>G12D</sup>, p53<sup>fl/fl</sup> (PK) mice. Molecularly, PAK3 is identified as a downstream effector of Smad4, mediating metastatic signal transduction via the PAK3-JNK-Jun pathway. Upregulation of PAK3 by Smad4 LOF in SPK mice is achieved by attenuating Smad4-dependent transcription of miR-495 and miR-543. These microRNAs (miRNAs) directly bind to the PAK3 3'UTR for blockade of PAK3 production, ultimately regulating lung cancer metastasis. An inverse correlation between Smad4 and PAK3 pathway components is observed in human lung cancer. Our study highlights the Smad4-PAK3 regulation as a point of potential therapy in metastatic lung cancer.
Medical subject headings
- Lung Neoplasms
- MicroRNAs
- Smad4 Protein
- p21-Activated Kinases